As the first round of COVID-19 vaccinations trickled out across the United States, many members of Congress lined up at the Capitol physician's office to get inoculated.
President-elect Joe Biden got vaccinated, too, as did Vice President Mike Pence. Both rolled up their sleeves live on television to receive their shots.
For some of America's political leaders, there are practical imperatives for getting vaccinated early. But there are also tricky optics for politicians to navigate, particularly with supplies of the vaccines still exceedingly limited and millions of elderly Americans and essential workers weeks away from being inoculated -- and more than 320,000 Americans already dead.
“I intend to take the vaccine,” tweeted Texas Sen. Ted Cruz, a Republican. “But, because I’m healthy & relatively young, I’m going to wait until seniors & frontline workers have the opportunity to take it first.”
Here's what else is happening today with the coronavirus pandemic in the U.S.:
Drug companies Pfizer and BioNTech have reached a $2 billion deal to supply the U.S. government with an additional 100 million doses of the COVID-19 vaccine, which they expect to deliver by July 31. Pfizer already has a contract to supply the government with 100 million doses of its vaccine, which requires two doses per patient.
President Donald Trump is attacking a $900 billion COVID-19 relief package approved by Congress, demanding higher direct payments to Americans that his fellow Republicans had opposed and complaining of "wasteful" spending elsewhere in the massive legislation. It's unclear whether Trump plans a veto, which would derail long-awaited aid to individuals and businesses unless lawmakers override his action.
A 12-year-old boy from a secluded valley in Idaho became one of hundreds of children in the U.S. affected by a rare COVID-19 complication.
In brief
THE NUMBERS: The seven-day rolling average for daily new deaths in the U.S. increased over the past two weeks from from 2,219 on Dec. 8 to 2,715 on Dec. 22, according to data from Johns Hopkins University.
DEATH TOLL: The U.S. death toll stands at 323,510 people, roughly the same as the population of Lexington, Kentucky.
QUOTABLE: "I know that God's got me. He's not going to let me get sick." — Jennifer Brownlee, 34, a fisherman from Bayou La Batre, Alabama, who was waiting at the airport in Tampa, Florida, to fly to Oregon to see her mother, who just lost a leg.
ICYMI: Patients in many U.S. hospitals who can't have visitors because of the pandemic are getting a little holiday cheer in the form of greeting cards. A variety of organizations, schoolchildren and others have made or bought cards and sent them to the institutions for distribution to patients.
ON THE HORIZON: New York City Mayor Bill de Blasio says sheriff's deputies will visit homes or hotel rooms of travelers coming from the United Kingdom to ensure compliance with the city's two-week COVID-19 quarantine requirement. De Blasio announced the action amid growing concern about a new, fast spreading strain of the virus that has been detected in the U.K.
What we know now about the new coronavirus strain
Experts answer your COVID-19 questions
America watched on Dec. 14 as the first doses of Pfizer’s COVID-19 vaccine were administered to health care workers across the country. These vaccinations were considered a victory by many doctors, nurses, and other frontline workers who chose to get the shots in order to better protect their patients.
As of Dec. 22, 2.2 million people were vaccinated, according to Bloomberg’s vaccine tracker. With case counts on that same date totalling 17.8 million, Dr. Anthony Fauci and other public health experts have advocated for Americans to wear masks, avoid travel and gatherings if they are able, and find other ways to reduce their risk of contracting the novel coronavirus.
Scientific evidence on the coronavirus has grown and changed significantly throughout the pandemic, making it challenging for many to determine how to safely balance COVID-19 risk with work, family, and other obligations. The Atlantic’s Ed Yong pointed out that over 70,000 COVID-related scientific papers have been published since last December: “more than twice as many as there are about polio, measles, cholera, dengue, or other diseases that have plagued humanity for centuries.”
70,000 papers is a lot of evidence to sift through. Luckily, SciLine, a science communication service affiliated with the American Association for the Advancement of Science, has been on top of the scientific discourse since the virus hit America. The organization has been compiling quotes from COVID-19 experts since March on different science and public health topics ranging from vaccine development to how online learning impacts children’s mental health.
Stacker selected 50 such quotes that answer common questions Americans may have had on the pandemic in order to clear up some confusion about COVID-19. Quotes are organized in chronological order to reflect the growing and changing nature of scientific knowledge during this pandemic.
Keep reading to find out about COVID-19’s origins, how it spreads, and how you can help mitigate risk in your own life.
Editor's note: Answers have been edited for length/clarity.
Understanding COVID-19 with Stacker:
States with the highest COVID-19 infection rates
From Wuhan to the White House: A timeline of COVID-19’s spread
How vaccines get made and approved in the US
15 ways doctors are now treating COVID-19
Talking to kids about COVID-19
- Question: How should parents talk to their children about COVID-19?
- Expert: Robin Gurwitch, Ph.D., Professor in Psychiatry and Behavioral Sciences at Duke University
- Date: March 30
“Parents and caregivers need to talk to their children and their teens without waiting for them to bring it up. Words could be as simple as, 'There’s been a lot of talk about coronavirus or COVID-19, tell me what you know about it.' For teens, you may use that opening or you may even say something like, 'Tell me what your friends have been saying about it.' By listening, you will hear their understanding and be able to gently correct any misinformation and misperceptions that they may have about the disease. Adults may be worried that talking about coronavirus would actually make it worse. The research doesn’t bear that out.”
Washing hands
- Question: How should people clean their hands to avoid viral transmission?
- Expert: Syed A. Sattar, MSc, Dip Bact, MS, PhD, RM (CCM), FAAM, FRSPH Emeritus Professor of Microbiology, Faculty of Medicine, Univ. of Ottawa, Ottawa, Ontario, Canada
- Date: March 30
“Handwashing with plain soap and water remains the best and the safest means of decontaminating hands. Proper handwashing constitutes (1) prewetting of hands with water; (2) application of soap (liquid, bar, or foam) followed by lathering for about 20 seconds; (3) thorough rinsing of the lathered hands with water; and (4) drying of the rinsed hand with a paper towel, cloth towel, or a warm-air hand dryer. Immediate recontamination of the washed hands must be avoided by turning off the tap with one’s elbows, for example.”
Trouble signs for kids
- Question: What are signs of trouble parents should be watching for in their children?
- Expert: Robin Gurwitch, Ph.D., Professor in Psychiatry and Behavioral Sciences at Duke University
- Date: March 30
“What we often see is that they may be more irritable and whiny, even sometimes more defiant than usual, which is challenging. As adults, we’re a little bit more short-tempered and a little bit less patient. So we have to make sure we take a breath and recognize that their irritability and defiance may be a problem of distress. Sleep problems are pretty common in children, so we can’t rule that out. Children may have physiological reactions such as headaches and stomachaches. There may not be a medical reason for them, but they’re still very real. One of the things important to recognize in elementary school children is that attention and concentration may be reduced. Children may have more difficulty in learning new along with being able to attend to it.”
Isolation and loneliness
- Question: Do isolation and loneliness pose physical risks to our health?
- Expert: Julianne Holt-Lunstad, Ph.D., Professor of Psychology at Brigham Young University
- Date: March 30
“Just like hunger signals us to eat, loneliness is thought to be a biological drive that motivates us to reconnect. Throughout human history, we have relied on others for survival; proximity to others, particularly trusted others, signals safety. So when we lack proximity to trusted others, our brain and body may respond with a state of heightened alert. This can result in increased blood pressure, stress hormones, and inflammatory responses—which if experienced on a chronic basis, can put us at increased risk for a variety of chronic illnesses.”
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COVID-19 stress
- Question: Whether it is normal to feel so much stress about COVID-19.
- Expert: Roxane Cohen Silver, Ph.D., Professor of Psychological Science, Medicine, and Public Health at University of California, Irvine
- Date: March 30
“It's important to acknowledge uncertainty is stressful and that anxiety is appropriate under current circumstances. This is a normal reaction to our new normal. And it’s important that journalists acknowledge this fact. It’s also important that we tell the truth. The situation may get worse before it gets better. Evidence is strongly suggesting that we are probably not yet in the eye of the storm. But there is a potential to help frame a more positive message: If we work together, we can save lives. And minimizing the uncertainty is disingenuous.”
Positive outcomes
- Question: Whether there are positive outcomes to be had from this pandemic.
- Expert: Julianne Holt-Lunstad, Ph.D., Professor of Psychology at Brigham Young University
- Date: March 30
“One of the potential positives here is I think we’re starting to see quite widely the recognition of the importance of our relationships. There is some evidence to suggest one of the leading factors for why people don’t participate more socially is they’re too busy. What we’re going through is awful, but it’s also something bringing communities together. We can potentially see more solidarity as people make time to reach out or look out for those in our communities who are more vulnerable. I think this current situation is helping us recognize just how important that is.”
Can't get tested
- Question: What should I do if I think I have the virus but can't access a test?
- Expert: Carlos del Rio, MD, Distinguished Professor of Medicine (Infectious Diseases) at Emory University School of Medicine and Professor of Epidemiology and Global Health at the Rollins School of Public Health
- Date: April 3
“If you think you have the virus but cannot access testing, stay at home and isolate yourself.”
Testing for antibodies
- Question: What's the difference between tests for the virus and tests for antibodies against the virus?
- Expert: Dr. Claire Standley, Assistant Research Professor, Center for Global Health Science and Security at Georgetown University
- Date: April 3
“The most common tests that look directly for the virus are based on identifying the virus’ genetic material, or RNA. These tests usually rely on a swab from deep within a patient’s nasal cavity to detect live virus and indicate whether a person is actively infected with COVID-19. Another type of test looks at antibodies, specific proteins that a person’s immune response produces after being infected. Antibodies circulate in the blood and lend themselves to the potential development of easy-to-use, fingerprick-based tests that could be done by people at home. Antibodies can take a week or more from the onset of symptoms to reach sufficient levels for detection. As such, these tests are not effective diagnostic tools to look for active cases of COVID-19 but will be extremely useful in identifying those who have previously been infected and since recovered.”
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Testing for pandemic response
- Question: Why is testing important for pandemic response?
- Expert: Dr. Claire Standley, Assistant Research Professor, Center for Global Health Science and Security at Georgetown University
- Date: April 3
“Testing functions as a tool for gathering information on who is infected, where, and when. Accurate estimates of infection levels are the cornerstone of evidence-based, public health decision-making during an epidemic—and can help hospitals and other frontline services plan, prepare, and more effectively respond.”
Aggressive testing
- Question: Would more aggressive and widespread testing help stop or slow the pandemic?
- Expert: Dr. Claire Standley, Assistant Research Professor, Center for Global Health Science and Security at Georgetown University
- Date: April 3
“Widespread testing can help identify mild or asymptomatic cases early and prevent individuals from unknowingly spreading the disease further. Aggressive testing and intensive case management, when conducted hand in hand, can be effective at limiting community transmission. Even once community transmission is widespread, testing can still be a valuable tool to assess (for example) whether physical distancing or other non-pharmaceutical interventions are having the intended impact, and as source data for predictive modeling.”
Homemade masks
- Question: Are homemade masks helpful to slow the transmission of COVID-19?
- Expert: Dr. Timothy Sly, Epidemiologist and Professor Emeritus, School of Public Health, Ryerson University, Toronto
- Date: April 9
“Authorities in the West initially encouraged the public not to use masks, probably driven by the predicted shortage of masks for medical staff. This is changing now that we include the perspective that while the mask is not even close to 100% effective, in emergency situations even a small reduction of risk is better than no reduction.”
Climate change and COVID-19
- Question: Could climate change make pandemics like COVID-19 more likely?
- Expert: Marta Shocket, PhD, Postdoctoral Fellow in the Department of Ecology and Evolutionary Biology at University of California Los Angeles
- Date: April 9
“Climate has big effects on how diseases spread once they emerge, but I don’t think climate and climate change are primary factors in new disease emergence itself. However, climate change is just one part of what ecologists call “global change.” This bigger term also includes things like land-use change—deforestation and the expansion of agricultural and human settlements into new habitats—which we think increases contact between humans and wild animals and increases the chance of a rare event like a pathogen crossing into humans. Once a new pathogen gets into humans, our increased connectivity from a globalized economy with lots of international travel makes it more likely that this pathogen will spread globally.”
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How to determine seasonality
- Question: How do scientists determine the sensitivity of a virus to changing seasons?
- Expert: Neal Nathanson, MD, Professor Emeritus of Microbiology, University of Pennsylvania
- Date: April 9
“Each virus has its own distinctive peak and trough. If you look at enough different viruses, you will find some that peak at every time of year; same for trough. Also, viruses with similar structures can show different peaks, so you can’t sort viruses by structure and find a consistent pattern of peaks and troughs. My working hypothesis is that each virus has its own ability to survive under specific conditions of temperature and humidity and that this is an important determinant of seasonality.”
Benefits of masks
- Question: What are the benefits of wearing a face mask, even if you are healthy?
- Expert: Dr. Linsey Marr, Professor of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University
- Date: April 9
“We now know that you can be infected with COVID-19 before you have symptoms, and you may not get any symptoms at all. Wearing a mask—the CDC is now calling it a cloth covering to distinguish it from medical masks used by healthcare workers—reduces the amount of virus you might spread into the air and onto surfaces if you happen to be sick. This would help slow transmission. A second benefit is that a mask, depending on the type of fabric, how tightly it fits, and how diligently you wear it, can help reduce your exposure to a virus that might be present in the air.”
Seasonal viruses
- Question: Why do some viral diseases show seasonality?
- Expert: Neal Nathanson, MD, Professor Emeritus of Microbiology, University of Pennsylvania
- Date: April 9
“Seasonality is most marked in temperate climates and abates as you move toward the tropics. In my view, we don’t really understand the determinants of seasonality, but they are not dependent upon seasonal differences in social behavior.”
Privacy and contact tracing
- Question: Should certain vulnerable groups continue practicing social distancing, even after restrictions are relaxed?
- Expert: Esteban Moro Egido, PhD, Visiting Professor, MIT Media Lab; Associate Professor, Universidad Carlos III de Madrid
- Date: April 28
“Social distancing is creating more vulnerable groups because not everybody has the luxury to work from home, home-school their children, or shelter-in-place. It is important that, whatever the measures we put in place or when social distancing measures relax, we consider varying impacts on different socio-economic groups. We have never been more segregated than today, with most of the population staying in their neighborhoods. Let’s not leave behind the most vulnerable groups.”
Immunity from antibodies
- Question: Does testing positive for COVID-19 antibodies mean you are immune to the virus?
- Expert: C. Buddy Creech, MD, MPH, Director, Vanderbilt Vaccine Research Program, Associate Professor, Pediatric Infectious Diseases, Vanderbilt University School of Medicine and Medical Center
- Date: May 6
“The challenge with any respiratory virus is a) the virus can change frequently, resulting in versions of the virus that escape our immunity and b) over time, the amount of antibody circulating in our bloodstream and at the surface of our nose and throat goes down. What we don’t yet know about COVID-19 is how long immunity lasts and whether subsequent infections follow the typical pattern of being milder than the first one.”
Immunity length
- Question: How long might immunity last?
- Expert: Arturo Casadevall MD, PhD, Chair of Molecular Microbiology & Immunology, Bloomberg Distinguished Professor, Johns Hopkins School of Public Health
- Date: May 6
“This is unknown at this time.”
Antibody status
- Question: What are the pros and cons of using antibody status as a factor in deciding who can return to work?
- Expert: John Williams, MD, Professor of Pediatrics, University of Pittsburgh; Director, i4Kids; Chief, Pediatric Infectious Diseases, UPMC Children’s Hospital of Pittsburgh
- Date: May 6
“The pro would be that people who have been infected are likely to be immune for some period of time. The cons are that we don’t know how long they are protected, and whether they are protected against infection and transmission or just against disease. This last point is critical for people working in high-risk settings (hospitals, nursing homes, etc.) where asymptomatic transmission could be deadly.”
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Antibody test reliability
- Question: What is the reliability of COVID-19 antibody tests?
- Expert: John Williams, MD, Professor of Pediatrics, University of Pittsburgh; Director, i4Kids; Chief, Pediatric Infectious Diseases, UPMC Children’s Hospital of Pittsburgh
- Date: May 6
“Some of the tests can measure antibodies in the blood accurately, although only four of the tests on the market have been through the FDA emergency use authorization (EUA) process. An EUA-approved test has demonstrated to the FDA that it performs to a specified standard. It takes a couple of weeks for people to make antibodies, and therefore these tests can’t be used to diagnose COVID-19. The tests can show if a person has antibodies, which may mean they have been infected. However, it’s important to remember that even an excellent lab test, with high sensitivity and specificity, has a low rate of false positives. If a COVID-19 antibody test is 95% specific but the infection rate in a population is only 5%, then most of the positive results will actually be false positives. Results have to be interpreted in the context of what we call ‘pretest likelihood:’ how likely is it this person was infected? Were they exposed to a case, or did they have a consistent illness?”
Herd immunity
- Question: What is herd immunity and what portion of the population needs COVID-19 antibodies in order to achieve it?
- Expert: Nahid Bhadelia, MD, MA, Medical Director, Special Pathogens Unit, Boston University School of Medicine
- Date: May 7
“We’re trying to obtain something called herd immunity—the concept that there are enough people in a group of people that are immune to a disease. Those who haven’t yet had the disease could keep themselves from getting infected because everybody around them has already had it and are no longer going to be infectious. There are calculations around how this is measured having to do with the transmission of the disease itself. For COVID-19, we’d probably want to see between 60% to 70% of the population being immune before we can say we’re comfortable.”
COVID-19 in kids
- Question: Does COVID-19 manifest differently among young people? How so?
- Expert: Steven L. Zeichner, MD, PhD; Professor, Departments of Pediatrics & Microbiology, Immunology, and Cancer Biology; Director, Pendleton Pediatric Infectious Disease Laboratory; Head, Division of Pediatric Infectious Diseases, The University of Virginia
- Date: May 21
“Children generally tend to have milder or asymptomatic disease, although there are exceptions. Babies and older children/adolescents may be more severely affected than other children.”
Multisystem Inflammatory Syndrome in Children
- Question: What is multisystem inflammatory syndrome in children (MIS-C) and how is it related to COVID-19?
- Expert: Jeffrey P. Burns, MD MPH, Chief of Critical Care--Boston Children’s Hospital, Professor of Anaesthesia—Harvard Medical School
- Date: May 21
“In mid to late April and in Maym physicians in Western Europe and along the East Coast of the U.S. noted a marked increase in children hospitalized with persistent fever and a mix of signs and symptoms such as rash, abdominal complaints, and low blood pressure leading to multiorgan failure and shock. Some of the illest patients have a presentation consistent, partially or completely, with Kawasaki disease. This multisystem inflammatory syndrome appears to follow with the peak prevalence of COVID-19 in the general population by about four weeks, suggesting a temporal association with the SARS-CoV-2 virus.
"Many of these children have IgG antibodies against SARS-CoV-2 without evidence of viral shedding. These findings have led to concern that the multisystem inflammatory syndrome might represent post-infectious inflammatory response where the inflammation is not caused by a primary infection by SARS-CoV-2, but rather by the patient’s own immune system. In this scenario, the child successfully mounted an immune response to the SARS-CoV-2 virus four weeks or so earlier, and had few if any symptoms of infection at that time, but now many weeks later is experiencing fever and inflammation because that same immune response is now in an accelerated state. Fortunately, to date, most of these cases are rare and self-limited."
Human expansion and pandemics
- Question: How will human expansion into previously uninhabited environments change the likelihood of pandemics?
- Expert: W. Ian Lipkin, MD, John Snow Professor of Epidemiology, Director, Center for Infection and Immunity, Mailman School of Public Health, Columbia University
- Date: June 11
“The history of emerging infectious diseases has taught us that, while the causes are largely anthropogenic, they are not deliberate. We contribute to their emergence through our destruction of wildlife habitats, bushmeat consumption, the exotic pet trade, climate change, and international travel and trade that facilitate the global spread of infectious diseases.”
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Lab origin
- Question: Is it likely that SARS-CoV-2 existed in a laboratory at some point—either naturally or as an engineered organism?
- Expert: Rasmus Nielsen, PhD, Professor of Integrative Biology and Statistics, University of California, Berkeley
- Date: June 11
“There has been a lot of speculation on whether SARS-CoV-2 was genetically engineered. There is nothing in the nucleotide sequences that would suggest engineering. The patterns that we see in the sequences are compatible with the usual process of mutation, selection, and natural exchange of genetic material between different viral strains. Viruses evolve very fast and there is a vast reservoir of viral genetic material in wild animals, so it is not surprising to see a virus such as SARS-CoV-2 suddenly emerge. In fact, virologists have been expecting this and warned about it for years.”
Evolutionary origin of SARS-CoV-2
- Question: What do we know about the evolutionary origin of SARS-CoV-2 and how do we know it?
- Expert: Rasmus Nielsen, PhD, Professor of Integrative Biology and Statistics, University of California, Berkeley
- Date: June 11
“We can compare SARS-CoV-2's nucleotide sequence to sequences from other viruses. The two most closely related viral sequences identified to date have been obtained from bats and we can show that these bat sequences diverged from SARS-CoV-2 roughly 35 and 50 years ago, respectively. That means that there was a common viral ancestor of a bat virus and SARS-CoV-2 about 35 years ago. However, what we don’t know is what happened in the last 35 years and how the virus eventually was transmitted to humans from some other species. It could have been from a bat species, or it could have been through an intermediary host in another species. To answer this question, we need to search for other more closely related viruses. While much work has been done on identifying viruses in nature, most remain undescribed and there is likely a large reservoir of other coronaviruses in wild mammals. The work on identifying coronaviruses in wild animals is also important because it will help us prepare for the next possible pandemic. Clearly, the world was not prepared well enough this time, but hopefully we will be better prepared next time.”
Social impacts of online learning
- Question: Are there social, developmental, or other pros or cons of virtual education?
- Expert: Dr. Christine Greenhow, Associate Professor of Educational Psychology and Educational Technology, Michigan State University; 2018 Recipient of Michigan State’s Teacher-Scholar Award
- Date: June 22
“We are facing inadequate access to technology and social infrastructure needed for virtual education. In the same way our country invested in our physical infrastructure, such as the interstate highway system, this pandemic has highlighted the need for a similar investment in our technology infrastructure. Students without reliable, fast internet or suitable devices for schoolwork or people around them to help are spotlighted in the shift to virtual education.”
Childhood impacts of online learning
- Question: How might childhood education be impacted if online learning—or a hybrid online/in-person model—is extended into the next academic year (2020-2021)?
- Expert: Justin Reich, EdD, Assistant Professor at MIT and director of the MIT Teaching Systems Lab (MIT TSL)
- Date: June 22
“We have already clearly seen that the most negative educational effects of the pandemic are borne by the most marginalized communities in society: students living in poverty, ethnic and racial minorities, and students lacking technology access. School buildings are some of our most powerful tools for addressing social inequalities. If we cannot get our most marginalized students back in buildings in the fall, we will see the dreadful gaps in opportunity and outcomes continue to widen, with a lasting negative impact on students and families.”
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Advantages of online learning
- Question: What are the pedagogical advantages of online learning, compared to in-person classroom learning?
- Expert: Dr. Christine Greenhow, Associate Professor of Educational Psychology and Educational Technology, Michigan State University; 2018 Recipient of Michigan State’s Teacher-Scholar Award
- Date: June 22
“Online learning can be as good as or even better than in-person classroom learning. Research has shown that students in online learning performed better than those receiving face-to-face instruction, but it has to be done right. The best online learning combines elements where students go at their own pace, on their own time, and are set up to think deeply and critically about the subject matter. These elements must be combined with students going online at the same time, interacting with other students, their teacher, and content, and getting feedback.”
Shortage of emergency response supplies
- Question: Has the pandemic created a shortage of critical disaster-response supplies or personnel?
- Expert: Njoki Mwarumba, PhD, Department of Emergency Management and Disaster Science, University of Nebraska, Omaha
- Date: July 1
“Current critical disaster-response supplies and personnel shortages are not creations of the COVID-19 pandemic. It is a reflection of the abject failure of imagination and leadership. It is a failure to accord requisite thought and action as recommended by infectious disease scientists, public health and emergency management professionals, and academics.”
Emergency responders and COVID-19
- Question: What measures can be taken to ensure that emergency responders deployed to a disaster site are protected from COVID-19?
- Expert: Dr. Shane Hubbard, Research Scientist, Space Science and Engineering Center, University of Wisconsin – Madison
- Date: July 1
“Research has shown that proper social distancing, hygiene, and personal protective wear are the greatest defenses against COVID-19. In an emergency, our responders may not be able to adequately do all of those measures when saving a life or responding to a disaster. As when around people who are more susceptible to COVID-19, we all should be doing our part to make sure our first responders are protected. That means we all need to continue to social distance, use proper hygiene, and use a mask when in public places. Protecting them will protect all of us. Our first responders are trained to take the essential steps not to spread COVID-19 and will continue to do their part as well.”
Masks and COVID-19 transmission
- Question: What do we know now about wearing masks and COVID-19 transmission that was not clear earlier in the pandemic?
- Expert: Chris Zangmeister, PhD, Research Scientist, National Institute of Standards and Technology (NIST)
- Date: July 8
“At the beginning of the pandemic, the research community was unsure if the type of material used in a cloth mask mattered. We investigated 32 different fabrics made from 100% cotton, synthetics, and blends for breathability and particle capture efficiency. On average, 100% cotton fabrics performed better than synthetic materials or blends. The best cotton materials had some raised fibers, or nap. A simple way to test for nap is to feel it between your thumb and index finger, and if it feels fuzzy, like a baby’s blanket, that is a good sign.”
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Asymptomatic carriers
- Question: Do asymptomatic carriers of COVID-19 always develop symptoms eventually, or do some never display symptoms?
- Expert: Sten H. Vermund, MD, PhD, Professor and Dean, Yale School of Public Health
- Date: July 21
“It’s helpful to keep asymptomatic as a separate concept from presymptomatic. Everyone who gets ill will have a presymptomatic time when they are infectious but they are not yet aware of being ill. This can be less than a day or several days. When we refer to asymptomatic, we refer to persons with no substantial symptoms of disease at any time.”
Risks of asymptomatic transmission
- Question: What is known about the risks of COVID-19 transmission by asymptomatic individuals?
- Expert: Virginia Pitzer, ScD, Associate Professor of Epidemiology (Microbial Diseases), Yale School of Public Health
- Date: July 21
“Studies suggest that approximately half of all COVID-19 transmission may come from people with no symptoms (presymptomatic and asymptomatic cases).”
Questions about asymptomatic transmission
- Question: What questions still remain about asymptomatic transmission, and what are researchers doing to answer them?
- Expert: Virginia Pitzer, ScD, Associate Professor of Epidemiology (Microbial Diseases), Yale School of Public Health
- Date: July 21
“We still aren't sure how infectious asymptomatic people are relative to those with symptoms. While studies suggest viral shedding peaks on or before symptom onset, more studies are needed to identify and track viral shedding in asymptomatic individuals.”
New lessons about slowing transmission
- Question: With COVID-19 cases rising again, are there lessons learned that inform how officials should go about slowing new waves of transmission?
- Expert: Stephen Kissler, PhD, Postdoctoral Fellow in Immunology and Infectious Diseases at the Harvard T.H. Chan School of Public Health
- Date: July 30
“Preventing and managing new waves of COVID-19 will require a multi-faceted response, including wearing masks, physical distancing, frequent hand washing, and limiting the sizes of gatherings. No single one of these elements will be enough on its own, but together they can help slow the spread of COVID-19 substantially. Governments and employers should ensure that essential workers have the supplies they need to keep themselves and their communities safe (e.g. masks and hand sanitizer) and should also guarantee paid time off if an employee becomes ill or is exposed to someone with COVID-19. Finally, frequent testing remains absolutely necessary.”
Changing infection reaction in the winter
- Question: Does the body's reaction to infections change during cold weather?
- Expert: Colin J. Carlson, PhD, Assistant Research Professor, Center for Global Health Science & Security, Georgetown University
- Date: Nov. 16
“Yes, the immune system can become a bit worse in the winter, increasing susceptibility to the virus and potentially leading to worse outcomes. But that information can be a bit extraneous sometimes; it’s hard to overstate the risk posed by COVID regardless of season or weather.”
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Two vaccines
- Question: If two vaccines are authorized for emergency use by the end of the year, what does that mean for curbing the US spread of COVID-19 in 2021?
- Expert: Dave O’Connor, PhD, University of Wisconsin Medical Foundation Professor of Pathology and Laboratory Medicine, University of Wisconsin-Madison
- Date: Nov. 16
“It is still going to be a very difficult winter. Distributing millions of vaccines will take months, so there will be a period where some people have natural immunity and others have vaccine immunity, while others remain vulnerable. Moreover, we don’t know how long vaccine immunity will last. While it would be great to get a vaccine on a Monday and celebrate your newfound immunity at a party on Tuesday, that’s not how it works. Those who are lucky enough to get a vaccine early in the process owe it to their communities to continue wearing masks and distancing until new cases and hospitalizations subside to near zero.”
Reduce risk in the winter
- Question: What should individuals do to reduce their risk of catching and spreading COVID-19 this winter?
- Expert: Colin J. Carlson, PhD, Assistant Research Professor, Center for Global Health Science & Security, Georgetown University
- Date: Nov. 16
“Limit your contacts when you can, get tested if you’re at risk, wash your hands, wear a mask, and be considerate of others. We’re also particularly worried that flu and COVID could create a ‘syndemic,’ where the two supercharge each other and lead to more cases and worse symptoms. So if you can, get a flu shot. But the best thing we can do is act as a collective to protect each other, and that means governors and mayors need to move rapidly to intervene before the pandemic becomes even more uncontrolled.”
Pfizer versus Moderna
- Question: What do we know about the similarities and differences between the Moderna and Pfizer/BioNTech vaccines?
- Expert: Paul Spearman, MD, Professor and Director of Infectious Diseases, Cincinnati Children’s Hospital
- Date: Nov. 17
“The Moderna and Pfizer/BioNTech vaccines are both mRNA vaccines and both cause the body to make a viral protein that SARS-CoV-2 uses to invade human cells. They both utilize a delivery and preservation technique to encase the RNA in the vaccine with lipid (fat) molecules, and these are likely somewhat different between the two vaccines. Both vaccines showed promise in creating an immune response in earlier trials and now both protect at a greater than 90% level in interim analyses. One difference that may become important is the temperature of storage, with the Pfizer product requiring -70 degree Celsius storage and Moderna reporting stability at -20 degrees Celsius. Moderna has also said its vaccine is stable for 30 days at refrigerator temperatures.”
FDA review of Pfizer
- Question: What does the FDA’s analysis of the Pfizer vaccine released Dec. 8 tell us?
- Expert: Peter Hotez, MD, PhD, Dean, National School of Tropical Medicine and Professor, Departments of Pediatrics, Molecular Virology & Microbiology, Baylor College of Medicine
- Date: Dec. 10
“The FDA confirms earlier efficacy claims and even some level of potential immunity a week after the first dose, although it remains imperative to get both doses in order to obtain truly high levels of virus-neutralizing antibodies. The outstanding questions that remain include the long-term durability of protection, whether manufacturing is robust enough to get sufficient vaccine to the public, the suitability for adolescents and children, and vaccine hesitancy for mRNA vaccines for children. This is important since we’ll need to reach adolescents and children to reach 60-80% population immunity. Finally, what’s the ability of vaccines to halt virus shedding and asymptomatic infection, essential for eliminating COVID-19?”
AstraZeneca versus Pfizer and Moderna
- Question: How does the efficacy of the AstraZeneca vaccine compare to that of the Pfizer and Moderna candidates?
- Expert: Dave O’Connor, PhD, University of Wisconsin Medical Foundation Professor of Pathology and Laboratory Medicine, University of Wisconsin-Madison
- Date: Dec. 10
“It is still premature to read too much into the bottom line numbers; it will be much more telling to look at performance over a longer interval, like one year. As recently as two months ago, scientists would have been elated with one vaccine that is 60% effective in preventing disease. Having three, with others on the horizon, is terrific. The more viable alternatives, the better.”
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