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Public Health Advisory Updates

Weekly updates from our epidemiologists explain how the team monitors the spread of COVID-19 at W&M and advises the university's operations.

Masking Up: A Look at the Variables Behind CDC's Latest Guidance

February 28, 2022
By Carrie Dolan

On Friday, CDC issued new masking guidance focusing on reducing the type of severe illness that initially strained the American healthcare system. With this guidance the agency rolled out a new tool to help communities decide which mitigation and prevention steps to adopt, based on new data and the knowledge we’ve gained from the ongoing pandemic. The indicators that make up that tool consist of three data points: 

  1. New COVID-19 cases per 100,000 population 
  2. New COVID-19 admissions per 100,000 population  
  3. Percent of staffed inpatient beds occupied by COVID-19 patients (seven-day average) 

Counties are then categorized as low (green), medium (yellow), or high (orange) risk based on these three metrics. Next, the CDC deployed the categorization to determine individual and household-level prevention behaviors, such as masking.  

CDC scientists also used the categorization to make recommendations for community-level prevention strategies, such as ventilation and vaccination. If a community is “orange,” the CDC recommends that everyone needs to mask indoors; whereas if a community is “yellow,” then only individuals at higher risk need to mask.  

CDC is using this combination of the three metrics as well as corresponding county level recommendations to create on- and off-ramps for interventions, such as masking. It also provided a resource to check community levels by county. It is possible that a community could relax an intervention, such as masking, but need to go back to using masks later if cases begin to rise and the categorization changes.  

These metrics are not perfect. There are limitations to the CDC framework. In particular, the CDC hasn’t provided justification for how it determined the new case metric of 200 cases per 100,000. 

I do like that the CDC focused on a layered approach. Although many of us are interested in the masking portion of the framework, it doesn’t solely focus on masking as the only intervention. I also liked the reminder that at all levels people can wear a mask based on personal preference, informed by their assessment of personal risk. As we start to move to endemic levels of COVID-19 in our communities, this framework can be used to reduce severe illness and monitor any strain on the healthcare system.

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Explainer: Which Mask Works For Me?

January 25, 2022
By Carrie Dolan

This week the debate over masking boiled over once again. The data and science generally agree that wearing masks can protect people from COVID-19. However, how much protection is offered and which type of mask to wear are again up for debate.  

The CDC recommends that we all wear the most protective mask we can that fits well and that we will wear consistently. The “most protective” part of the recommendation can get tricky, because not all masks are created equal — construction, materials and fit matter. N95s and KN95s offer the most protection, because they can filter up to 95% of the particles in the air. Unfortunately, America is inundated with fake N95 or KN95s, some of which offer less than 1% protection. Because I suddenly have become an expert in masks, I am now serving as an adviser to friends, family and the community on which one to wear.  

The first thing we have to get straight is the terminology. Masks contain droplets and particles that you breathe, cough or sneeze out. When I think of masks, I think of the cloth one my friend made me that has a cute little checkerboard pattern or the disposable surgical ones that were free for a long time at the front of a store. In contrast, respirators can be considered specialized masks that protect you by filtering out the air. These are the N95s and the KN95s that are usually (but not always) bright white.  

This week I had the chance to do a quantitative mask fit test and test out all my masks. I tested the free one I took from the front of a grocery store, the checkerboard cloth one that used to be my everyday mask, a KN95 I bought online and an N95 someone let me have for this test. I sat in a chair, and the machine measured the number of particles that got into my mask based on a series of tests. I was shocked. I knew masks were not created equal, but I did not know how unequal they could be. Except for the newly borrowed N95, all my masks failed the test. They let in too many particles to keep going. It is essential to point out that this is not a scientific study, and there was a sample size of one (me), but I learned some things worth telling my friends and family.

  1. Fit matters. Find a mask that does not have gaps around the sides. I thought my little cloth one was gap-free, and I was wrong. 
  2. The type of head strap matters. Earloops are so 2021. What you want is a mask with straps that go around your head. That helps make sure it fits.
  3. If you bought an N95 or KN95, check the mask for labels to make sure they are real. N95s should have a NIOSH TC approval number. It will look something like TC-XXX-XXXX. I usually find this number on the face of the mask, but it is sometimes on the headband. Also, make sure NIOSH is spelled correctly. My friend was wearing one yesterday with the TC number, but NIOSH was spelled NOISH. Hers was fake. KN95s do not have to meet the same standards (as a U.S. agency does not regulate them), so it can be harder to tell if they are counterfeit or not. One way to tell is that if a KN95 says it is approved by the CDC (or the website says that), it is not real. 
  4. If you want an N95 or KN95 and cannot find one, then the next best solution is to wear a surgical mask with a cloth one on top. 

It is important to remember that a mask is a tool. The tool that works best for you might take some time to find. You will know you have found your mask when it fits well and you wear it consistently. I thought I was going to be sad that I was leaving my checkerboard cloth mask, but it turns out that I am in love with my new N95. This one is a newer design that looks like a duckbill, but it makes talking and teaching so much easier. I have been wearing it all week at the Swem Writing Retreat, and at one point, I forgot it was on! I am looking forward to the day when COVID-19 is endemic, and I do not have to adopt the facial profile of a duck, but until then, I am grateful for this simple tool that does work to keep me healthy.

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The Ides of March

January 18, 2022
By Iyabo Obasanjo

The ides of March is the day Julius Caesar was assassinated and the beginning of the end of the Roman Empire, and I am hoping the same date serves as the beginning of the end of the COVID-19 pandemic. As I write this, the Omicron variant is spreading like wildfire across the world and the U.S. If you have not had COVID-19 yourself, by now you know someone that has. Even people who have not been symptomatic could have had mild, undiagnosed cases.   

My personal opinion is that the Omicron variant, with its less severe symptoms and rapid spread, would lead to more people around the globe becoming immune close to the same time and ultimately limit the spread of COVID-19 in all its variants. Of course, I cannot guarantee this, but it is reasonable to assume the common cold coronavirus was some time in the human past as deadly as the Alpha variant of COVID-19, then slowly – over millennia -- became a less virulent disease to humans. COVID-19 seems to be doing this in real-time. We can see it happening because we are all more connected globally than at any point in human history. And there are more humans than ever in our history, leading to rapid spread and rapid mutations.   

We are not going to be able to permanently get rid of COVID-19. That genie is out of the bottle. At endemicity, COVID-19 will still likely threaten to kill people vulnerable due to age or underlying conditions, but we will largely live with it as another human disease we encounter all the time.  

Of course, if humans are going to be adding new diseases, we need to get rid of old ones! Only one disease has been eradicated on our planet through human effort using vaccination. I fear our triumph over smallpox may be our sole human victory if the levels of vaccine hesitancy, misinformation and disinformation continue at the rate they are now.   

Caesar had every reason to beware the ides of March; I hope we’ll have every reason to welcome it. As winter turns to spring, I hope we will see disease rates that indicate respite from and permanent triumph over COVID-19, and solid indicators that it is heading toward endemicity.  

I also hope we then start the global conversation on managing human diseases as one global human entity. 

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COVID-19 Omicron and an Olympian Dubbed ‘Lightning’

December 14, 2021
By Carrie Dolan

Have you ever seen Usain Bolt run?

In 2002, I saw him warming up on a track in Kingston, Jamaica. Bolt is widely considered the greatest sprinter and fastest human ever timed.

He is fast. He demands attention on the track. So much so that I left my lunch of chicken with rice and peas to watch him jog around.

The same is happening with the omicron variant — it is fast and demands attention. This week, the UK gives us a glimpse of what is to come as omicron numbers are doubling every two or three days. We still do not have much data (and no peer-reviewed publications) on whether omicron causes more severe illness. That being said, we know that the three vaccine doses are essential for protection. Preliminary data show that the third booster prevents roughly 75% of people from getting COVID-19 symptoms from omicron. In response, we have seen booster shots become not just available, but recommended for everyone ages 16 and older.

Usain Bolt’s fastest time was clocked at a speed of 27.9 mph. The delta variant clocked its transmission speed with an R0 value of 6, which means one infected person will pass it on to about six other people. For comparison, the flu has an R0 of around 2. While we are still timing omicron, we know it will be higher than 6, which means it is moving faster than any of the other COVID-19 variants.

So if we know it is coming and it is coming fast, how do we beat omicron in this race?

Like Bolt’s competitors, we have to be ready for what will happen. My race plan is to enhance my readiness for what is sure to be a surge in omicron cases to ring in the New Year by helping friends and family get their third booster shots. I have walked dogs, watched kids, even wrapped some presents to create time and space during this busy time of year for the essential third-shot appointments in the lives of my loved ones.

Therefore, when omicron is here, our bodies are ready to run. Bolt style.

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Let’s Not Make This a Season of Misinformation or Disinformation

December 7, 2021
By Iyabo Obasanjo

The COVID-19 pandemic has brought to the forefront the need for a good health communication strategy. The amount of bad information concerning COVID-19 and the COVID-19 vaccines out there over the last two years has frankly enabled the spread of the virus. I have heard it all, from, “The vaccine puts a microchip in you,” to, “It changes your DNA,” to, “It causes infertility,” to, “Why were they so fast in creating a vaccine?” My personal favorite was when someone told me the story from the fictional movie “Legend” to justify not getting the vaccine. 

Now with another new variant spreading across the globe, the misinformation and disinformation continues. The media that is supposed to inform and educate sometimes seems more interested in sensationalizing, rather than offering in-depth, thoughtful reporting.

Take the question: “Why were they so fast in getting a vaccine?”

The answer is simple: Science.

In every field of science, research and studies are going on continuously, with new ideas and new treatments being researched in ways that only experts in the field of study can understand. This research is published in scientific journals specialized to that field. It takes decades for some of that seemingly obscure research to be turned into something actually useful for human health or other areas of human life.

Science needs money to propel it, of course. But critically, it also requires the justification of the usefulness of the science. Ideas could stay in the obscure stages for a long time, until they are accelerated by a need.

Sometimes the stars align. Research on using mRNA protein messaging for vaccine delivery, to bypass using any of the viral particle in the vaccine, has been around for decades; making its way through scientific journals. It’s entirely possible that it could have taken another few years – or even a decade – to be used against a disease. But then a new RNA viral pandemic occurred. The mRNA protein research was there (thankfully!), waiting to be accelerated. It really wasn’t “so fast.” It was more like, “Right on time.” The science is sound, and the vaccine has gone through all the needed scientific processes. The public’s, or the media’s, not understanding a process does not make it wrong.

I may be preaching to the choir. William & Mary people understand this better than most – we have alumni involved in every step of the process. We have had alumni working on the Moderna vaccine, the Pfizer vaccine, the J&J vaccine, the distribution of COVID-19 vaccines and their study. There are probably more I don’t yet know about!

Also new variants of viruses arise because that is how viruses roll, especially RNA viruses that don’t have the double helix to match-up to another strand. So they jumble protein sequence during replication and pass that along to the newly replicated viruses. Since COVID-19 is new, what each new variant portends takes a while to decipher. It could be a random variant, or one that occurred to avoid a barrier, such as vaccination. What is known is that experiencing any variant while vaccinated causes a milder disease than not being vaccinated, since one’s immune system still recognizes the variant as a coronavirus.

Whether it’s Alpha, Delta, Omicron or Omega (has not happened yet), vaccination helps. And they didn’t drop from the sky!

Turkey, With a Side of Omicron

November 30, 2021
By Carrie Dolan

This Thanksgiving, I had a lot to celebrate.

We have navigated around this infectious disease for over 18 months, carefully weighing the risks and benefits of each social interaction, and finally, our household is fully vaccinated. We gathered with friends and family without pandemic-inflicted parenting decisions, and it felt so good! We ran a turkey trot, played football and ate two full Thanksgiving meals with tables ringed with grandparents.

It was bliss for about 24 hours, and then Ominous Omicron showed up at the table. Like an uninvited guest, this new variant cast a shadow on our Thanksgiving as it began to emerge in South Africa and then moved on to Australia, Hong Kong, Israel, the Netherlands and Canada. Once again, I see people worried, and I am finding myself cornered in Target discussing what might happen next. So let’s review what we know about omicron at this moment of Tuesday, Nov. 30, 2021, what we don’t, and the best next steps as we head into the final few weeks of classes and our final exams.

First things first: We do not know very much about the omicron variant, other than it is moving fast. Much faster than the delta variant. As a result, we are seeing cases and hospitalization rates increase in some parts of the world. To slow the spread, some countries (such as Japan and Israel) ban entry to all foreigners, while others (such as the U.S.) have stopped flights from southern Africa. It is essential to pause and recognize that we do not have all the information about this variant. We do not know if it is causing more severe disease or if the current vaccines will offer the same level of protection.

The emerging travel restrictions don’t mean it is time to panic, and they don’t mean we need to immediately change our current policy response at William & Mary. It is way too early for that. We know surveillance systems are working, and we have tests that can find new omicron cases. These are two major wins for global epidemiological science!

It is also essential to recognize that this is not unexpected. A lack of vaccines in some parts of the world and lower vaccination rates in others have created an environment where we should expect the emergence of new variants.

If you feel uncomfortable about waiting and seeing what happens with omicron, I suggest some next steps: Get your booster to make sure you have the best level of protection possible. (The CDC yesterday strengthened its stance to now recommending that everyone over 18 get a booster six months after Moderna or Pfizer doses or two months after the J&J.) Even if we find out that the current vaccines do not work the same way on omicron, we do not expect them to be useless. So make sure your body has the highest level of immunity possible.

Next, get tested if you feel sick. Please do not assume it is a cold, allergies or the flu. Furthermore, do not forget your mask. If you are in public areas where you do not know the vaccination status of people around you, then wear a mask. They work.

Last but not least, remember that we have come a long way in the last 18 months. We know what we need to do to monitor the cases, and we can quickly scale a policy response if needed. Although I would have liked to have my Thanksgiving without a side of omicron, it was not unexpected. Our track record of success indicates we will be ready to navigate this new variant at William & Mary as well.

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To Boost or Not To Boost?

November 3, 2021
By Iyabo Obasanjo

That is the question many of us will have to answer for ourselves over the next weeks and months.  

For people with underlying conditions and those immunocompromised, this should be an easy decision -- the answer, unequivocally, must be to boost.  

For everyone else already vaccinated, getting a booster shot is also a good decision. The virus is going to continue circulating and having one’s immune system able to defend our bodies from contracting a severe case when exposed is important. It could be the difference between COVID-19 presenting as a case of a few sniffles versus a visit to the emergency room.   

Given that between 20-25% of the population eligible is not yet vaccinated, the virus still has much room to circulate, so encouraging people to get their first dose is still important. Boosters will help individuals stay healthy, but mass vaccination that provides herd immunity to stop disease circulation requires much higher vaccination rates than we have for COVID-19 currently.  

With children vaccination soon to start (unfortunately, it did not come before Halloween), there will be a significant increase in the population vaccinated, putting additional barriers in the virus’s way.   

We could be approaching the last COVID-19 pandemic winter, and boosters and children’s vaccinations will help us have a flattened COVID-19 curve this winter. We will still need to be careful as we associate, congregate and celebrate over the holidays, but the end is in sight. Like I had mentioned, pandemics always end and this one surely will, too. 

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Transitioning to Endemic COVID-19

October 26, 2021
By Carrie Dolan

If you have been watching the news in the last few weeks about COVID-19 and higher education, you probably have heard that some universities are getting rid of their indoor mask mandates. It is exciting for some, terrifying for others. After many months of a layered mitigation approach, during which William & Mary has weathered surges of cases, the virus is under much better control.

So if the virus is under control, when will W&M sound the “all-clear,” signaling an end to the pandemic?

I think it is important to understand how the pandemic officially ends, from a global perspective, to answer that question. As my colleague, Iyabo Obasanjo noted last week, the pandemic ends when most people have a degree of immunity from either immunization or a previous infection. Without immunity, the virus will continue to circulate, and COVID-19 will still be considered a pandemic. 

Right now, about 75% of the immunizations available have gone to people in high- and upper-middle-income countries. Less than 1% of doses have gone to people in low-income countries. 

For this reason, the pandemic will likely continue for years to come. Therefore, as an epidemiologist, I focus more on when the virus will become endemic. We consider a disease endemic when, on average, one infected person infects only one other person. Meaning the rate of infection is more or less stable.  

Although the United States is making considerable progress toward endemic COVID-19 levels, we are not to that reproductive number yet. What keeps us from reaching that number is that the virus circulates in groups of unvaccinated people who also do not wear masks.

Our local numbers are promising. At W&M, we have high vaccination rates and high adherence to masking guidelines. Adherence to these two strategies allows us to teach in person, participate in sports and recognized student organizations, and enjoy some level of social freedom.

Although we are successful, in the next couple of months we will likely see another spike of COVID-19 attributed to the holidays and colder weather. We will also likely be navigating another round of vaccines in the form of boosters.

In addition, we know we will see increased mobility as we all move off and back on campus, which is historically related to a surge in infections. Our previous history suggests we will navigate that successfully as a campus community. If we do, we will see signs that we are moving toward endemicity on campus.

According to Joshua Petrie, an epidemiologist at the University of Michigan, the path toward endemicity will look less like an on-off switch and more like a dimmer. I think Joshua is right. We will not see an all-clear signal in the form of a siren. It will be a gradual lifting as we adjust our behavior based on what we see on campus.

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How Do Pandemics End?

October 19, 2021
By Iyabo Obasanjo

Now that we are seeing the light at the end of the tunnel for the COVID-19 pandemic, we can start to ponder this question. We should do this questioning cautiously, because the reason we are on the down slope of our fourth wave of the pandemic is due to early celebration of COVID-19’s defeat and removal of precautions before the disease was at levels that justified removing limitations. Caution was thrown to the wind, and policymakers and the public start behaving as if the pandemic was over. Predictably, that led to the start of the next wave.  

Fighting disease is like a war: You don’t leave the battle when you are in the middle of winning, but when you have vanquished the enemy completely. We need to totally exterminate COVID-19 before declaring victory. And then we need to be prepared with a “whack-a-mole" reaction every time it raises its head after that. 

Throughout human history, pandemics seem to end with a whimper rather than a bang. People just start going about their business as usual as they hear of less and less disease and death. Then one day we find ourselves doing all the normal things we always did, and realize the pandemic is gone. Even after the worst pandemics — with lots of loss, grief and anguish — humanity returns, with all of our rituals, celebrations and milestones.  

On William & Mary’s campus, we had some rituals and celebrations return during Homecoming last week. It's a start, as numbers go down and remain low. Soon, as has happened to our predecessors who went through pandemics, we will move on and start doing everything we always did.  

One weapon that we have always had, but I hope now stays, is the normal wearing of masks in public to prevent catching or spreading disease. Other cultures around the globe have done this for a century as a way for individuals to protect themselves and others against respiratory diseases in general. This is a simple but effective public health tool. If we can adopt it as normal for people to do, even after COVID-19 becomes endemic, we will protect each other from waves of respiratory infections, especially people with weakened immune systems.  

We learn lessons, which we use to battle the next potential pandemic. How well we learn those lessons and add them to the arsenal of weapons in fighting future diseases is how we triumph against future pandemics.

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Dispatch From Parentland: Child COVID-19 Vaccines

October 12, 2021
By Carrie Dolan

For the past few months, parents have been asking about children’s vaccines. As I walk around campus, the first question people ask me is if I am vaccinating my little kid. We have stayed clear of this topic for several weeks because the timeline for availability was murky. But Thursday, Pfizer and BioNTech formally applied for emergency use authorization (EUA) for a kid-sized dose, so now is the time to wade into this topic.

Applying for an EUA means that Pfizer and BioNTech sent enormous amounts of information to the Food and Drug Administration, which is now thoroughly reviewing and will publicly deliberate the evidence on Tuesday, Oct. 26. If the FDA decides the shot is safe and effective for children ages 5 to 11, deliberations will then move over to advisers at the Centers for Disease Control and Prevention, who have the final say as to whether they will officially recommend the vaccine for kids. Many of us with little kids had hoped to have this process completed by Halloween, but remembering that we do not have a crystal ball, it looks like early November is a more realistic timeline.

I did read through some of the information Pfizer and BioNTech sent over. I was most interested in knowing about the dose, specifically whether it was the same as the one I received. It is not. Pfizer recommends that 5- to 11-year-olds get one-third of the dose that’s given to everyone 12 and older.

I also wanted to know if the vaccine worked in kids. For those of us who like a good clinical trial, this is where things get interesting.

In the adult trial, the outcome measured was related to COVID-19-related illness — specifically serious illness, hospitalizations and deaths. In pediatric trials, researchers used different outcomes, because COVID-19-related illness was too rare in the population to measure with statistical reliability.

So in the pediatric trials, we are decoding instead whether the vaccine is effective based on the antibody response. The trials are finding that the kids have a slightly higher antibody response than adults, even though they are getting less vaccine. I am happy with this measure of effectiveness because it measures precisely what we hope a vaccine will do: produce antibodies!

My kid is 11 and in the highest percentiles for weight and height, so next I wanted to know if I should wait for him to turn 12 and get a bigger dose, or if he should get this smaller dose now.

From the trials, the results indicate that the smaller dose produces many antibodies. Most likely, as my kid grows, he too will be getting a booster at varying doses, so it makes sense to go ahead and start the protection now and follow up if and when needed.

Finally, I wanted to know what was happening for the kids under 5. They are still enrolled in trials, and we expect those results by the end of the year. We are still waiting for those kids, but are optimistic that they will have their chance at this shot by next spring.

This brings us back to the question of whether or not I am vaccinating my kid. The short answer is yes. A longer answer is that as an epidemiologist, I believe in the effectiveness of vaccines in general as the best tool we have to prevent disease.

Sometimes people ask why parents want COVID-19 vaccination, since the risk of serious illness is so low in children. In fact, the number of kids under 18 who died in a vehicle crash was six times higher than the number of kids who died of COVID-19 during that same time.

But I do not want my kid to get COVID-19. A positive diagnosis complicates our life. I am equally tired of mitigating the learning loss that comes with quarantining from his elementary school and his sports. I have much confidence in the data coming out of the trials and the FDA and CDC review process.

And in the end, if I could spend less than 30 seconds giving him a quick shot that would keep him from ever dying in a car crash, I would probably be one of the first people in line. He seems excited about it. I am excited about it and we will be helping organize the mass vaccination clinics that we hope roll out in early November.

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Pandemics and Us

October 5, 2021
By Iyabo Obasanjo

In 1854, John Snow, a physician working in the poor section of London (which is now a swanky section of London) discovered that Cholera was not passed through “bad air,” as was previously assumed due to how badly the area smelled, but was caused by the area’s drinking water. The organism came from humans, who had defecated into rivers and streams. Thus the impetus for the modern sewage system was born. Thus was also born a new science that studied the pattern of diseases in populations – epidemiology – with John Snow its father.

Cholera is no longer a problem in parts of the world with indoor plumbing and sewage systems, although the organism itself still exists. Humans have always existed alongside diseases, and we have managed to keep thriving despite pandemics and organisms evolving to infect us. When Cholera’s mode of transmission was discovered, its causal organism was not yet known, but the basic result of separating human waste from human sources of drinking water saved us not just from Cholera but myriad other diseases. 

We would eventually get the upper hand over Cholera (and other diseases), but not without some learning curves along the way. Of course, we have many more tools to fight diseases than ever before, and a much more sophisticated understanding of disease in general. “Bad air” and the miasma theory are long disproved, thankfully.

Now COVID-19 is in the process of transforming to a disease we are able to manage without disruption in normal human activities, but we are not quite there yet. Some accommodations to prevent the disease spreading will need to stay in place for a while. We should not be despondent about this, as generations before us went through worse pandemics, and made more severe adjustments. The plague devastated Europe in the Middle Ages, Native Americans in both North and South America suffered severe human losses due to diseases (some weaponized) and the list could go on and on.

This is not to minimize the terrible effect that the COVID-19 pandemic has had on each of us, whether personally in the loss of loved ones, in our academic or professional lives, in our mental and emotional health and countless other ways. But it is to provide some comfort and perspective that humans as a whole are resilient, ingenious, dedicated, selfless and creative. Just as indoor plumbing became the new normal that mitigated Cholera, so we have to believe that we will find our way out of COVID-19, no matter how frustrating and puzzling the process might be.

Our campus community, the country and world has had to respond to a pandemic that is not only the first in our lifetimes, but one that actually touched and shut down almost every country on the globe. We will slowly enter the endemic phase of COVID-19, when it will no longer be the threat it is today, but in the meantime, we will keep adjusting and changing as the data and science dictates. Another Jon Snow reminds, “Winter is coming.” But we know spring follows.

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Public Health Surveillance: A Tool for Targeting and Monitoring Interventions

September 28, 2021
By Carrie Dolan

As cases have decreased on campus, some have asked us more about how we find the active cases. W&M has supported a robust public health infrastructure to find and monitor cases and adherence to proven public health interventions. Public health surveillance systems are essential in preventing and controlling disease spread throughout the university community. Through these systems, we can capture our new cases (incidence) and monitor the burden of disease on campus (prevalence).  

To find the cases, W&M has supported both active and passive surveillance systems throughout the pandemic. To actively find the cases, we used testing. Last academic year, William&Mary's COVID-19 prevalence testing program sampled students, faculty, staff and contractors based on population representative sampling, so that the university can rapidly assess potential community spread.W&M weekly testedat least 5% of its student population and 2% of its employees within 30 miles of campus. Meanwhile, census testing of the entire on-campus student population was conducted just about every month.   

Now, free weekly testing for students, faculty and staff is being conducted for those people who have vaccination exceptions or deferrals (depending on circumstances); this protocol follows Virginia and federal guidelines. This process allows William & Mary to identify positive cases quickly, an important public health action when social distancing and some masking requirements have been lifted. It also offers sustained testing for the campus population that might suffer the severest consequences of infection.

In addition to actively finding cases through testing, we also work to find cases through passive surveillance. If anyone in our campus community tests positive for COVID-19 or is identified as a close contact, they must notify the university through to initiate case management and contact tracing.

We not only keep up with the cases, but we also support efforts to monitor the use of proven public health interventions designed to prevent disease. In the pre-vaccine pandemic, we supported primary data collection over 10 weeks to monitor adherence to masking, the best known COVID-19 intervention at the time. This research was conducted in partnership with the CDC and reported to the W&M Public Health Advisory Team weekly, finding that the W&M community consistently wore masks 97% of the time in public spaces.

We also know that having a high level of vaccination in our university community is how we can safely and responsibly convene in person in the traditional ways that matter so much to university life. Being vaccinated is also the single most effective thing we can do to protect our health and those around us. Therefore, all students, faculty, and staff were required to record full vaccination by September 17. These reports are reviewed for accuracy, and therefore we can confidently report high vaccination rates on campus.

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Disease Detectives in the Classroom

September 21, 2021
By Iyabo Obasanjo

We’ve received a number of questions about how William & Mary has determined that the recent increase in student cases of COVID-19 were attributable to off-campus, unmasked activities. Specifically, we have said that we have not yet found evidence of community spread of COVID-19 in the classroom, where students and instructors are masked. 

It’s an interesting question. Prevalence and census testing, upon which William & Mary and a great many other organizations depended last year, are less useful in a highly vaccinated population. That is why W&M’s weekly testing now concentrates on the members of the community who are not yet fully vaccinated.  

So how can we reasonably state with some confidence that classroom spread wasn’t the driver for this recent uptick in cases? 

First, we have the information students themselves provide to case managers for contact tracing. As our health logistics people say, “There’s no mystery here. The students know where they’ve been and who they’ve been in contact with.” (Of course, that’s not every student, but generally a pattern quickly emerged.) 

But more, we have relevant data on the students who have tested positive. Both of us epidemiologists on the Public Health Advisory Team examine the information we have, looking for relationships that even the students might not realize are in play.  

We look for clusters in a class by the Course Reference Number (CRN), which is specific to each course. If there is more than one case in a course, we look for additional linkages between the two, such as whether they are roommates, on the same team or in the same student organizations. These relationships are more likely to give rise to “close contact.”   

We also look at the date the students became COVID-19-positive and examine that data in relation to class times and other activities they share. So far, COVID-19 cases in the same course can be linked to other, unmasked situations, like when students attended the same party. Put a different way: If two classmates went to a party that we see through contact tracing resulted in 20 more cases, then most likely those two got COVID-19 at the party, not in the class. 

We did see that large classes tended to have larger case numbers. We don’t believe this is from the classroom; but more because the larger classes have more students and are thus more likely to have a positive case. Smaller courses have fewer positive cases. Tellingly, the percentage of positives is not extremely high in some courses and extremely low in some courses. Instead, it’s generally equal across both large and small courses.  

Even at the height of the recent uptick, most courses on campus had no cases, and those classes with cases were averaging about 3-4% of the students two weeks ago. This dropped to 2-3% last week. This rate translated practically to 1-5 students affected in a class (if that class had any at all), depending on the size of the course. For example, in courses with different sections, such course numbers show up a lot in our analysis. Yet when you break it down by CRN, we see one or two cases per class. 

A much simpler metric is watching the employee numbers. Those have remained relatively low and static, suggesting that students and professors aren’t passing the virus back and forth. Of course, “absence of evidence is not evidence of absence,” so we continue to examine the data as closely as we can in order to inform William & Mary’s public health response. 

Last semester, although fewer courses were in-person, we did not find a case linked to classroom exposure. Most exposure through contact tracing was in social settings and other living situations, where people were not wearing masks. Classroom masking, even without social distancing at six feet apart, reduces risk of transmission if masks are won correctly and in all group settings, especially indoors.

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Ending on the best note 

May 11, 2021
By Iyabo Obasanjo

For the first time since the beginning of this semester, we had only one new case of COVID-19 to report to VDH this week. We should all congratulate ourselves on this achievement. The semester started just weeks after the highest number of cases in the nation, due to holiday travels and social mingling in December and January. Our initial case numbers reflected this, and within a few weeks we got to more cases than we had in the whole of last semester.

Our cases then started to decline steadily – until we had the convergence of St. Patrick’s Day and a Spring Break Day and this led to higher number of cases. But again with everyone’s diligence, cases went down rapidly and we have since had a steady decline.

Vaccination started in late January and the university worked with the City of Williamsburg to schedule faculty and staff for vaccination based on the criteria set up by the state, and then to students starting in late March as the criteria expanded.

Our lower COVID-19 transmission rates in the last four weeks reflect a combination of our vaccination rates increasing and our continued maintenance of the Healthy Together ideals.

This has not been an easy semester for students, staff or faculty. Over 300 members of our community were infected. Additionally, our community faced the effect of friends and family getting sick and the constraints of social isolation and changes in normal activities brought about by the pandemic. 

We made it, based on the commitment of the administration and the work of many at William & Mary, such as the indefatigable Corinne Picataggi and her whole Health Logistics team, as well as the COVID-19 Response Team. The coordination of testing, quarantine & isolation and vaccination scheduling is not as easy as they made it seem. 

We should be proud of our W&M community, we rose to the occasion. With vaccination rates rising, we hope the circumstances when we return in the fall 2021 semester will be much different, but we can be assured that due to how we handled the COVID-19 challenge this semester, we will handle whatever comes along together.

W&M Vaccine Survey Results

William & Mary asked students, faculty and staff this spring to voluntarily report their vaccine status in order to coordinate vaccination appointments and plan for fall. Here are self-reported results as of May 7, 2021:


  • Two-thirds of the student population, or 5,781 students, responded.
  • Of those, 47% (2,728) report they are fully vaccinated. 
  • Thirty-eight percent (2,190) report they’ve had one dose. 
  • In total, 85% are either fully vaccinated or in the process of receiving vaccinations. 
  • Twelve percent (710) indicate they plan to be vaccinated.
  • Less than 3% (153) indicated they have no plans of being vaccinated at this time.
Faculty & Staff
  • Just over three-fourths, or 76%, of faculty & staff (1,949) responded.
  • Of those, 70% (1,371) report they are fully vaccinated. ​
  • Twenty-two percent (430) report they’ve had one dose.
  • In total, over 90% are either fully vaccinated or in the process of receiving vaccines.
  • Four percent indicate they plan to be vaccinated​.
  • Of those who responded, 3.4% reported they do not plan to be vaccinated at this time.

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Masks outside: Yes or no? It depends

May 4, 2021
By Carrie Dolan

This week the CDC advised Americans that masking was no longer necessary for fully vaccinated individuals when doing outdoor activities in small groupsThe statement also explained that unvaccinated people may go without masks outdoors when exercising with household members.

This guidance was issued at a time when India is experiencing a massive surge in cases and the World Health Organization’s director general highlighted the need for continued caution given the global increase in both cases and deaths. 

This may have seem confusing to many, but it’s logical -- based on local conditions and personal situations. 

This week I have asked myself the question, “Do I need a mask outdoors?” I have also fielded the same question on our local baseball fields and in Colonial Williamsburg.

The answer is: It depends.

This is unsatisfying -- but accurate. Whether you need to wear a mask outdoors depends on several factors. It depends on personal risk, immunization status (yours and those around you) and the setting.

At the university level, it is important to remember that we are in a communal setting, and people don’t move in and out of our population often. Our university can be considered as a semi-closed population in that we have generally the same people in it, but we are also interacting with the general population constantly and at different levelsThat means disease can be introduced and spread quickly if we aren’t vigilant.

It is also important to recognize that the CDC says masking is still recommended in public spaces. Everyone is still expected to wear them in the Sunken Gardens, at sporting events and at graduation. 

I am encouraging my friends to revisit the Know your Number approach as a way to communicate individual level approaches to masking. 

We recognize that inconsistencies in the global narrative can be confusing. We urge you to remain vigilant as we finish up our spring semester. We also continue to urge you to get vaccinated. Last week was World Immunization Week with the theme “Vaccines bring us closer.” Let’s continue the strong path we have created and bring ourselves closer together by staying healthy together.

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Vaccination prevents spread of COVID-19

April 27, 2021
By Iyabo Obasanjo

The CDC has started to document cases of breakthrough infection in vaccinated individuals. These occur because vaccines are not 100% protective against getting the infection; the protection rate for available vaccines ranges from 85% to 95%.  

All breakthrough infections were introduced by unvaccinated persons, but vaccinated people either had no symptoms or mild symptoms, and those symptoms tend to occur in vaccinated older individuals with pre-existing conditions in nursing facilities.  

Vaccination also prevented secondary spread, which is when an infected person spreads the disease to others. Overall, this indicates that the way to stop cases of COVID-19 from occurring is to vaccinate as many people as possible. 

Some people may have health risks that prevent them from getting vaccinated. We advise people to not decide this based on their diagnosis alone, but instead should check with their health care provider. Our immune systems are robust! They evolved to keep us alive in the face of lots of environmental pathogens on earth’s surface, so they tend to work well except in severely immunocompromised individuals.  

We encourage people to get vaccinated, but we also understand that each person’s individual health status is different, and sometimes if you have another relatively mild condition such as a cold, it’s inadvisable to get vaccinated at the time.  

We therefore also encourage tolerance and understanding of others who have reasons for not wanting to get vaccinated immediately. Tolerance and patience with each other are important in helping us as an academic community within state, national and global communities to overcome this pandemic.   

Nationally, we are at 50% vaccination rate, so we are literally halfway there! 

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How long will the vaccine last?

April 20, 2021
By Carrie Dolan

If you are among our campus community that has recently been vaccinated, your next question might be, “How long is this vaccine going to last?” In our previous Epi Updates we have addressed how well the vaccines work (spoiler alert: very well) and research does indicate that so far, they are still effective.

What is less clear is exactly how long they will last and if a booster will be required. In a typical situation, we would have continued with Phase 3 clinical trials lasting several more years before the vaccine was used widely. Those trials would have given us the data on long-term immunity that we need to answer these questions. In the absence of this longitudinal data, we don’t know how long the protection will last. There are vaccines for other diseases that last a lifetime, while some last 10 years and others need annual boosters. 

Research on how long the immunity for the various COVID-19 vaccines will last is emerging, with initial possibilities ranging from six months to several years. We also know that factors such as strength of individual-level immune response and the emergence of variants could influence the duration of protection. In the future, we might see tests emerge that detect the level of antibody response. These could provide an indication of when a booster or vaccine is required.

In the meantime, let’s continue to get vaccinated, since we know this will help us develop a robust immune response and reduce the threats to efficiency of the vaccination. If the whole population gets vaccinated quickly, then we reduce the chance of variants developing, and reduce variants that don’t respond to the vaccine.

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The lost history of the smallpox vaccine

April 13, 2021
By Iyabo Obasanjo

Vaccination, or immunization, is a natural phenomenonscience is just copying nature to protect humans from disease. Even before humans knew that micro-organisms cause disease, ancient cultures acknowledged that that some people exposed to a disease didn’t die from the disease, but instead became immune.  

In India and West, East and North Africa, many societies created methods of introducing individuals to disease in ways that made them sick but did not cause them to get a serious case of the disease, and resulted in immunity. For example, scarification in West Africa developed as a method to make people immune from smallpox: a blade was dipped into the pox on the body of a person sick with smallpox and that same blade was then used to make scarification on the body of a healthy personwho then had a mild form of the disease but never got full-blown smallpox.  

This form of immunization for a viral disease was described by Onesimus, a West African enslaved person, to the minister Cotton Mather, who subsequently introduced various forms of mild exposure to smallpox in Boston in the early 1700s. (History detailed the fascinating story a few days ago in How an Enslaved African Man in Boston Helped Save Generations from Smallpox.”) Such exposure without dosage could surely go wrong and many people did get full-blown smallpox with these methods.   

Vaccination has never been 100% safe, but science has made it safer over time, to the point of eradicating smallpox using it. Our current battle against COVID-19 is just as fierce as those of humans battling diseases from the beginning of time. Vaccination is a tool to keep us safe. With the four most common vaccines against COVID-19, no one can assure 100% safety. With the mRNA vaccines (Pfizer and Moderna), using a new method of delivery, we don’t know the long-term effects. With the vaccines using well-tried methods of vaccine delivery (AstraZeneca and Johnson & Johnson), association with blood clots has been found but occurs in less than 0.05% of people vaccinated. Out of an abundance of caution, the CDC has recommended a pause in use of Johnson & Johnson’s vaccine to further examine the association with blood clots. 

Yet no one vaccinated with any of the vaccines has died of COVID-19. The effects of COVID-19 can be severe, and we still don’t know all the reasons why it is severe in some people and mild in others. There is also the issue of long COVID and how that affects an individual’s long-term health and well-being.  Given how widespread COVID-19 is, the only way to guarantee our return to normal life and to protect ourselves, our families, our friends and neighbors is to get vaccinated so we achieve herd immunity as quickly as possible. William & Mary is now at the point of being able to offer vaccination to any faculty, staff or student who wants it. We urge you to be vaccinated as soon as possible. 

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I'm vaccinated: Is it safe for me to travel?

April 6, 2021
By Carrie Dolan

The pandemic limited where and when we could travel over the last year. Last week the CDC released new travel guidance for people who are vaccinated and those who are not. This guidance indicates that it is generally safe for fully vaccinated people to travel within the United States 

These people also do not need to get tested before or after travel, and do not need to self-quarantine unless they are required to by their destination or work.  

If you haven’t been vaccinated, then the CDC recommends holding off on travel for now. If you haven’t been vaccinated and you must travel, then you should get tested before and after you go, as well as quarantine once you get back.  

The updated travel guidance is exciting information, as many people who are fully vaccinated are ready to set off to somewhere other than our living rooms 

In this week’s update it is important to think about what this new guidance means for our campus community as some of us will begin to travel. It’s important to remember that we are part of a collective community that has a high level of contact. Crowded spaces and community living are among the most common risk factors for infectious disease spread.  

If you are vaccinated, and decide to travel, then it is important to understand that even domestic travel isn’t business as usual. Since you are part of a campus community, its important to build in time to research and plan your mitigation measures. All travelers should wear a mask, maintain social distance from people not in your group and wash your hands or use hand sanitizer often. 

It is our collective responsibility to look at the evidence that says that travelers are at lower risk when vaccinated. Equally important is our responsibility to continue to protect our campus community when we are making a change to behavior that may increase risk of infection. 

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Preventing exponential spread

March 30, 2021
By Iyabo Obasanjo

In the past week the student case counts of COVID-19 continued to increase. In this Epi Update, we are urging you to limit your social contacts, because this combined with masking and handwashing will help us break the chain of transmission in our William & Mary community.

Each person infected with COVID-19 infects on average two people, but when a super-spreader event occurs, one infected person can infect many people. We developed the William & Mary Healthy Together Community Commitment guidelines to limit close contacts based on the CDC’s guidance, which follows universal prevention methods of disease prevention. If everyone is limiting their close contacts, whether we have a positive test result or not, then it allows the public health system to work effectively through contact tracing. When our public health system is working effectively, we can rapidly address the disease spread on campus.  The more contacts we have, the harder it is to trace contacts. And the harder it is to contain the spread of disease.

In addition, W&M testing protocol is based on the optimal time of detecting the virus. Getting tested during the disease incubation period will not lead to disease detection, but only provide a false sense of security. The incubation period for COVID-19 is at least 10 days after exposure, so a negative test immediately after a suspected exposure will be accurate but does not mean one is not infected. The danger of missing cases is that, because every positive case infects about two additional people, in a week W&M’s cases could double again.  

Our advice to students: Do not try to hide your symptoms or hide positive results taken off-campus! This only helps the disease spread further.

This infectious disease feeds on human behavior and habits. And we can thwart it by our appropriate behavior as well. We can work together as the Healthy Together Community Commitment outlines – not blame each other for exposure – to limit our own risk and exposure of others.   

Please limit your social contacts to smaller groups. Remember your masks and wash your hands. Together we can stop the chain of transmission in our community.

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COVID-19 variants: Moving the virus faster

March 22, 2021
By Carrie Dolan

As you’re no doubt aware, new strains of the SARS-CoV-2 virus are emerging. Viruses change over time to adapt to various situations; most adaptations allow the virus to overcome barriers to its replication and promote its continued survival. On March 18, the CDC's tracker at US COVID-19 Cases Caused by Variants indicated that variants across the United States cause 9,541 COVID-19 cases. The data also indicate that the variants are more easily transmitted from person to person. It is essential to understand that we do not think these variants are more virulent and therefore making people sicker, but they may spread faster if the precautions already in place, such as adequate social distancing and wearing masks, are not followed.

Since February many states have been reporting a steady decline in cases numbers. Unfortunately at the national level, we are starting to see hot spots of transmission as states are easing mandates around masking, handwashing and distancing a little bit too soon.

Emerging data indicate the variant virus is susceptible to the antibodies produced by the vaccines, meaning the current vaccines prevent disease from variants. The fact that vaccines and current mitigation measures are working against variants of the virus is excellent news, because we do not need to develop new public health interventions to keep our campus community safe.

We recognize that people are ready to move outside of their bubbles, especially if they have been fully vaccinated. The take-home message is that higher transmission potential can result in more cases and because these variants can increase transmission, we ask for continued support in adhering to our healthy campus commitment to ensure we keep cases down at William & Mary.

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Evaluating appropriate response in real-time

March 16, 2021
By Iyabo Obasanjo

In Virginia the rate of COVID-19 continues to decrease, although national rates are currently level due to the opening up of some states. Easing our Healthy Together commitments too soon have the potential to boost variants and result in a resurgence of cases. PHAT is continuing to examine all available data and the details of our Healthy Together Commitment are evaluated several times a week to ensure they are still necessary to decrease or slow the spread of COVID-19 in our campus community. We are in good shape with our cases, but we do not want to stop here. These commitments will be relaxed when we have a stronger and consistent downward trend in cases. 

One tool we have to stop the pandemic is vaccinations, and national data indicates they are working.  Many people in our campus community are receiving vaccines from more sources, such as the drug store or their doctors' offices. Therefore, the university started collecting voluntary information on faculty and staff vaccinations in part to help us monitor the rate of vaccinations in our campus community. It is important to know the vaccination rates because the CDC has new guidelines for vaccinated people (Interim Public Health Recommendations for Fully Vaccinated People | CDC). Once we have comprehensive data on vaccination we will know when we can recommend the use of the new CDC guidelines on a wider, institutional scale. 

This is particularly important in planning for the fall at William & Mary. We anticipate that summer, while robust in curricular offerings, will be limited in-person and very limited at W&M in terms of campus housing. Summer represents an in-between time – not a period of uncontrolled pandemic but not an unabashed return to normal, pre-COVID life. William & Mary is currently planning for the fall to be the time when university life looks more like it did pre-pandemic. That hinges largely on sufficient vaccination levels among our students, faculty, staff and in the surrounding community. 

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A vaccine Q&A with the epidemiologists

March 9, 2021
By Carrie Dolan and Iyabo Obasanjo

Last week the FDA confirmed Emergency Use Authorization for the Johnson & Johnson vaccine, which is administered in one dose. This different kind of COVID-19 vaccine can be more easily distributed because it doesn’t need to be stored and refrigerated at very low temperatures. This is a game-changer when it comes to increasing the access to the general population. We’re seeing many questions around the new vaccine, though, so wanted to tackle those today, and then offer our regular weekly updates.

Is this vaccine effective?

The J&J vaccine is 66% effective, while Pfizer and Moderna vaccines are as high as 95%. However, the J&J vaccine appears to be even more effective against serious illness. Some people may also prefer the one-shot dose, given it provides a substantial amount of protection. For comparison, let’s think about the flu vaccine. At 40%-60% effective, it prevents thousands of cases of serious illness and death each year.

Why is the J&J vaccine different from Pfizer or Moderna?

The difference in efficacy has to do with the way each vaccine was created. Pfizer and Moderna use a new technology of mRNA delivery that relies on sending messages to our cells. There is no actual virus particle in these vaccines. It works by directing our cells to create the protein unique to the virus. Later, facing a real-life infection, our immune systems recognize the protein and prevent disease. You might be interested to know that a William & Mary alumna, Melissa Moore ’84, worked on the Moderna vaccine. You can learn more about her fascinating and critical work in this W&M Alumni Magazine feature story.

The J&J vaccine relies on the classic system of vaccination. It takes a minute piece of the virus, which cannot cause disease, and delivers it into our bodies in a way that activates our immune system, so when later we are exposed to a real-life infection, our immune system attacks it before it makes us sick.

Should I trust a new vaccine technology?

The mRNA technology has actually been under development for about a decade; the new part of it was adapting the emerging technology to respond to COVID-19, which was an entirely new virus to our species. But its class of coronaviruses has been known to us for some time, and scientists were already working on the mRNA vaccine technology that most effectively prevents illnesses associated with RNA viruses.

Is one vaccination technology safer than the other?

Both modes are safe. J&J uses the traditional technology, which is less (but still highly) effective against RNA viruses such as COVID-19. Pfizer and Moderna’s mRNA vaccines use new technology to boost immunity specifically against RNA viruses.

If I have the choice, which should I choose?

They all offer protection, and have no downsides, in our view. The J&J vaccine is just one dose and is easier to store and transport, offering greater convenience for both recipients and state and local health officials. The higher effectiveness rating of the Pfizer and Moderna vaccines might be more attractive to those who are at very high risk. Bottom line: Having more vaccine choices protects all of us, as everyone’s situation is different.

Regular Updates

Eating together is an important part of community and friendship, but because of the mode of transmission of the COVID-19 virus, sharing meals while in close proximity is a high-risk activity. Early studies indicated that restaurants and bars were some of the main places from which COVID-19 spreads quickly. To eat or drink, we have to remove our masks, creating opportunity for fomites in the air to be inhaled or ingested. Taking precautions such as eating alone is hard, since it's an activity we love to share with others, but please continue to follow best practices of eating in your personal spaces, outdoors and adequately distanced from others.

Right now, morale is high as we are seeing vaccine access increase and cases decrease. It is important to remember that vigilance is still imperative to keep our campus community safe. If we can stay the course and avoid the temptation to relax our vigilance too much and too fast, then we will really see a difference in the coming months. It is important to remember that if you have the vaccine, you may not be sick from COVID-19 but you can still be infected. That means you can give it to someone who might not be vaccinated and they could get really sick. It is important that we continue to stay the course by wearing our masks, washing our hands and maintaining physical distance. We are very close to being able to re-evaluate these interventions, but we aren’t there quite yet.

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The lag between national, state and local trends

March 2, 2021
By Iyabo Obasanjo

Last Wednesday, Gov. Ralph Northam announced plans to ease some COVID-19 restrictions, including social gathering limits and the statewide stay-at-home order. The lifting of previous restrictions was in response to decreasing statewide COVID-19 rates, declines in hospitalizations and increasing vaccination rates.  

Given the expected lag between decreases in national, state and ultimately local COVID-19 rates, W&M will continue to adhere for now to existing restrictions and our Healthy Together Community Commitment as advised by the Public Health Advisory Team. 

As COVID-19 presents unique challenges for universities and our ultimate goal is to ensure the safety of students, staff, faculty and the surrounding community, we are continuing to actively monitor trends at national, state and local levels. If these trends continue to decline, the W&M guidelines will be re-evaluated to determine if easing our restrictions would be appropriate. Before we re-evaluate, we want to reach a level of reduction in cases significant enough that a reversal to higher rates is improbable. Early removal of restrictions during a downward trend can easily lead to a spike in cases. As cases further reduce there will be less likelihood of each of us coming in contact with a person actively shedding the virus, and therefore less likelihood of transmission. It is critical that we adhere to our current guidelines for this critical downward push.   

Because of the delays in shipping samples due to weather we are waiting on the most recent test results. We are also using other data, specifically wastewater treatment data, to focus and increase prevalence testing on areas of campus that need it the most. This targeted testing approach will help ensure that our declining numbers are not an aberration and that we have a consistent downward trend on campus. 

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Update and mask study at W&M

February 23, 2021
By Carrie Dolan

Although Williamsburg has been saved from the worst of the winter weather, apart from a dusting of snow over the last week, about 70% of the country is covered in snow, and we are seeing that weather impact Williamsburg through interruptions in the supply chain for both shipping test kits and vaccines. We want to thank the Athletics Department for stepping up and helping fill in the gap in testing supplies by sharing their test kits and having their personnel help with testing.  As the weather conditions ease up, prevalence testing will continue, so we can again ship large numbers of test kits to the test locations.  

Vaccine roll-out has been slow. Variants are arising and spreading. As our campus community adopts masking and handwashing as the norm, maintains social distancing and limits close contacts, we are starting to see the first traces of a reduction in terms of our infection and positivity rates. Thanks to W&M student researchers, we have new data that shows that 97% of our campus community wore masks and most commonly selected the cloth or surgical type of mask (94%) known to be the most effective at preventing disease spread. Despite the slowdown, it is critically important that we maintain our healthy commitments to a safe campus community.   

National, state, county and city COVID-19 rates continue to trend downward. Our numbers also continue to trend down. Your resilience in keeping the Healthy Together promise and doing your part means we are on the downside of the epidemic curve. We cannot relent yet, since this microorganism is a cunning foe, so we will be keeping all precautions in place as we trend down, and it's important that you continue to abide by those precautions.

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An introduction to the Public Health Advisory Team

February 16, 2021
By Carrie Dolan and Iyabo Obasanjo

With more regular epidemiological updates, we want to provide the William & Mary community additional information about how we respond to COVID-19 risk at the university and offer a snapshot of the current landscape, from an epidemiological perspective. Given the rapid changes in the landscape of available data at both global and local levels, this update doesn't provide an exhaustive list of all meaningful data we review. However, it does make accessible many significant sources and our process for reviewing data. Since COVID-19 is not contained by either artificial or campus borders, monitoring the changes over time and understanding what prevents new cases from occurring is a cornerstone of public health.

The type of data the Public Health Advisory Team reviews can be broken down into four categories.

Case surveillance data & monitoring

We monitor daily national, state, county and W&M-specific COVID-19 surveillance data. These data can tell us how the pandemic is changing, allowing us to assess severity and risk and to develop necessary interventions.

Even with the best surveillance and monitoring, cases will appear; W&M actively seeks COVID-19 primarily through wastewater testing and weekly prevalence testing (testing a percentage of students, faculty and staff). We use weekly wastewater test results to more effectively target prevalence testing for students living on campus.

In addition, W&M conducted population-wide (census) testing of students on campus and within 30 miles four times in the fall and is currently conducting the first round of student census testing this spring. Our goal with prevalence and census testing is to seek asymptomatic positives before large numbers of contact occur.

Predictive models

Next, we analyze 13 predictive models that illustrate the possible trajectories of the pandemic. These models are updated routinely.  Each makes a different set of assumptions, so looking at multiple models helps understand potential outcomes and best- and worse-case scenarios.

Contact tracing

Third, we review data from contract tracing. These data help us to identify people who may have been exposed to COVID-19 through direct contact or proximity. We can use these data to test for infection and ask people who have been associated with a positive case to isolate. The goal of using this data is to prevent new cases from occurring.

Intervention effectiveness

Finally, through primary data collection, we measure the effectiveness of our testing and mitigation interventions. We are collecting data on the effectiveness of different types of testing approaches and the implementation of mask adherence on campus.


Currently, there are more students in post-infection than there are current cases. This means that the number of active cases and new positives is declining, which is excellent news, and just what we hoped to see. This trend mirrors the reduction in national, state and Historic Triangle rates. We expect this steady decline to continue, as increased COVID-19 was associated with the high rates that followed the holidays; such high population rates aren’t expected for the rest of the spring term. 

William & Mary’s first wastewater data of the semester came in and helped target sampling last week; they also reflected what we expected. Whole population, census testing also started last week. We expect that both will help us identify cases early and help mitigate spread, as happened last semester.

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