Your second dose of vaccine gives you more extra protection than you might think. Here’s why you should still get it, even if it’s later than planned.Millions of people have missed their second dose of Covid-19 vaccine. But does it really matter?Yes. Public health officials say that if you’re getting a two-dose vaccine, you should complete both doses for the strongest protection against Covid-19, especially with new variants circulating the globe. From a practical standpoint, missing the second shot could create problems down the road if workplaces, college campuses, airlines and border patrol agents require proof of full vaccination.But many people aren’t getting the message that the second dose matters. More than five million people, or nearly 8 percent of those who got a first shot of the Pfizer or Moderna vaccines, have missed their second doses, according to the most recent data from the Centers for Disease Control and Prevention.The reasons people are missing their second shots vary. Some people say they are worried about side effects, which have widely been reported to be worse after the second dose. Others say second shot appointments have been canceled, and it’s been hard to reschedule. But new research also shows that many people are just confused and wrongly think one shot is enough.Researchers from Cornell University and Boston Children’s Hospital surveyed a representative sample of more than 1,000 Americans in February, and found that 20 percent believed they were strongly protected after just one dose of a two-dose vaccine. (Another 36 percent said they weren’t sure how protected they were.) And among those respondents who had already received at least one shot, 15 percent didn’t remember being told to come back for a second dose. About half didn’t remember anyone telling them that protection was strongest after the second dose, according to the report, published in The New England Journal of Medicine.“Our survey exposed the fact that there is still a lot of confusion about the timing of protection when it comes to getting vaccinated,” said John Brownstein, an epidemiologist and chief innovation officer at Boston Children’s Hospital and a co-author on the research.Adding to the confusion is the fact that some countries are delaying second doses so they can get more people vaccinated more quickly or because they have limited supply of vaccine. Both the Pfizer and Moderna vaccines are what’s known as mRNA vaccines and require two shots, ideally spaced three or four weeks apart. But in some countries, including Britain and Canada, second shots have been delayed by as long as three or four months. While that strategy has worked for countries facing distribution problems or vaccine shortages, Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, has repeatedly resisted calls to adopt a one-dose strategy in the United States.The C.D.C. recently reported that a study of health care and emergency workers at high risk for exposure to the coronavirus found a single dose of Pfizer’s or Moderna’s Covid-19 vaccine was 80 percent effective at preventing Covid-19. After the second dose, the vaccines were about 90 percent effective.But vaccine experts say those numbers can mislead people into thinking there’s very little benefit from the second dose, and fail to capture some of the important changes that happen inside the body after a person is fully vaccinated with both doses.“The second dose of mRNA vaccines induces a level of virus neutralizing antibodies about 10-fold greater than the first dose,” said Dr. Paul Offit, a professor at the University of Pennsylvania and a member of the Food and Drug Administration’s vaccine advisory panel. “Also, the second dose induces cellular immunity, which predicts not only longer protection, but better protection against variant strains.”It’s also not clear how long first-dose protection lasts without the boost from a second dose, Dr. Fauci said during a White House press briefing in April.“We have been concerned, and still are, that when you look at the level of protection after one dose, you can say it’s 80 percent, but it’s a somewhat tenuous 80 percent,” Dr. Fauci said. He said there’s concern that more-contagious variants that continue to spread around the globe could partially-evade vaccine-induced antibodies after just one dose. “You’re in a tenuous zone if you don’t have the full impact” of two doses, he said.Although breakthrough infections after vaccination are rare, they do happen. A recent study of 250 people in Israel who were infected after they were partially vaccinated with the Pfizer vaccine — between two weeks after the first dose and one week after the second dose — showed that they were disproportionally infected by B.1.1.7, the variant first identified in Britain. The same study found that in a group of 149 people infected after the second dose of vaccine, eight infections with B.1.351 (the variant first identified in South Africa) occurred between days seven and 13 following the second dose. No breakthrough infections with the South Africa variant were seen 14 days after the second dose. Although it was a small sample, the finding suggested that full vaccination offers more protection against the variants, said Adi Stern, the study’s senior author, a professor at the Shmunis School of Biomedicine and Cancer Research, Tel Aviv University.Another study showing the benefits of full vaccination looked at a group of 91,134 patients who had previously been seen by doctors in the Houston Methodist Hospital system and followed them between December and April. Most were not vaccinated, but 4.5 percent were partially immunized and 25.4 percent were fully immunized. There were 225 deaths from Covid-19 in the group, and 219 (97 percent) were among the unvaccinated. But five deaths (2.2 percent) occurred among the partially immunized. Only one person (0.004 percent) died in the fully immunized group. In that study, full vaccination was 96 protective against hospitalization and 98.7 percent protective against dying from Covid-19. But the partially vaccinated were only 77 percent protected from hospitalization and 64 percent protected from fatal Covid-19.The study’s senior author, Saad B. Omer, director of the Yale Institute for Global Health, said he began the research with a “neutral” view about the benefits of two doses versus a single dose. But he’s now convinced the benefits of a second dose are meaningful.“Given the data from our study and other evidence, it does not make sense for people to skip their second dose,” Dr. Omer said. “When it comes to prevention of deaths through vaccines, the glass is 64 percent full, but wouldn’t you rather have it nearly 100 percent full for such a drastic and irreversible outcome as death?”Beyond the obvious health risks, skipping the second dose also could make your life more complicated if you want to travel or visit facilities that require proof of vaccination. “You will not be considered fully vaccinated,” Dr. Brownstein said. “It may have implications for getting back to normal again. If your vaccine passport or card doesn’t show a complete status, you may not be able to do certain things. You may not be able to get on a plane.”For people who have missed their second dose of the Pfizer or Moderna vaccines, here are answers to some common questions.Is it ever too late to get my second dose? No. If you skipped your dose for any reason, you don’t have to start all over again with another two-dose regimen. The C.D.C. has said that if supplies are low or appointments aren’t available, patients may extend the interval between doses up to six weeks. In Britain, the second dose has been delayed up to three months. Whatever the timing, doctors advise you to get your second dose, even if more time than recommended has passed since your first dose.Where should I go to get my second dose? First, try going back to your original provider — just don’t forget to take the vaccine card you were given after your first dose. At many sites, you can just walk in with your card and receive your second dose if it’s the same location as your first dose. Some state websites specifically allow you to schedule a new second dose appointment. Many CVS and Walgreens sites are also offering second doses to people who got their first shots elsewhere. In fact, stand-alone second doses represented about a quarter of the overall second doses CVS administered last week and 14 percent of those administered in April, said T.J. Crawford, a spokesman for the chain. Just call ahead to make sure they are offering the same vaccine you got the first time.I’m a college student who got my shot on campus. Can I get a second shot in a different state? Pharmacies participating in a federal vaccine distribution program now are setting aside any residency requirements for vaccine recipients. This will allow college students who got their first shot on campus to get their second dose at home.Do people who have tested positive for Covid-19 still need a second shot? Yes. Even if you’ve had Covid-19, you still will get stronger immunity from vaccination. A person’s immune response to a natural infection is highly variable. Some people may produce few antibodies, and natural antibodies seem to be less resistant to variants compared to stronger vaccine-generated antibodies. While it’s not clear how much extra benefit a recovered Covid patient gets from two doses, versus a single dose, you need a second dose to provide proof of full vaccination, should you need it for travel or for work. People who have had Covid-19 in the past are advised to wait about 90 days after infection before getting vaccinated. If you get Covid-19 after your first dose, you may need to adjust your vaccination schedule until you are fully recovered and have approval from your doctor for getting the second shot.What if I’m avoiding the second dose because I’m worried the side effects will be worse? Side effects like fatigue, headache, muscle aches and fever are more common after the second dose of both the Pfizer and Moderna vaccines. But while side effects can be unpleasant, they are manageable, short-lived and a sign that your body is building a strong immune response.Should I get the second shot if I had a severe reaction to the first dose? There are rare cases in which forgoing the second shot is medically advised. The C.D.C. recommends that people skip their second dose if they have a severe allergic reaction after their first shot. The guidance is the same for a milder allergic reaction that develops within four hours, such as hives, wheezing or swelling, even if it doesn’t require emergency care. For most other side effects, though, the agency recommends getting the second dose, unless a doctor or vaccination provider advises otherwise. If you think you had a severe or unusual reaction to your first shot, consult with a physician. You should also check with your doctor if you experience a worrying side effect or side effects that don’t seem to be going away after a few days.Rebecca Robbins

Science shows that the risk of viral transmission outside is very low. The “two-out-of-three rule” can help you decide whether to mask up.As more people get vaccinated and spring weather and sunshine beckon us outdoors, one question may be nagging at you: Do we still need to wear masks outside?More than a year into pandemic life, many people remain confused about the risk of spending time outdoors around other people. A growing body of research shows that transmission of Covid-19 is far less likely outdoors than inside, and the risk will get even lower as more people get vaccinated and cases continue to decline. But many states have yet to lift strict outdoor mask mandates. In Massachusetts, for instance, outdoor masking is required at all times, even when nobody else is around.Recently the online magazine Slate stirred controversy when it suggested an end to outdoor mask rules. The article won support from top public health experts and even The New England Journal of Medicine blog but prompted a fierce backlash from readers, who noted that while the risk of outdoor transmission may be low, it’s not zero.“Shallow and selfish take,” wrote one reader on Twitter. “You have blood on your hands. You should feel ashamed,” posted another.After a year in which many of us have learned to dutifully wear masks and look askance at anyone who does not, it’s understandable that people remain fearful when they cross paths with the unmasked. So how do you make the right decision about when to wear a mask outside?Many virus and public health experts say the guidance hasn’t changed — spending time with others outside during the pandemic has always been safer than indoors. But whether a mask is needed outdoors depends on the circumstances, including local public health rules. Brief encounters with an unmasked person passing you on the sidewalk or a hiking trail are very low risk, said Linsey Marr, a professor of civil and environmental engineering at Virginia Tech. Viral particles quickly disperse in outdoor air, and the risk of inhaling aerosolized virus from a jogger or passers-by are negligible, she said. Even if a person coughs or sneezes outside as you walk by, the odds of you getting a large enough dose of virus to become infected remain low, she said.“I think the guidelines should be based on science and practicality,” said Dr. Marr. “People only have so much bandwidth to think about precautions. I think we should focus on the areas that have highest risk of transmission, and give people a break when the risk is extremely low.”Dr. Marr uses a simple two-out-of-three rule for deciding when to wear a mask. In every situation, she makes sure she’s meeting two out of three conditions: outdoors, distanced and masked. “If you’re outdoors, you either need to be distanced or masked,” she said. “If you’re not outdoors, you need to be distanced and masked. This is how I’ve been living for the past year. It all comes down to my two-out-of-three rule.”Use the 2-out-of-3 RuleTo lower risk for Covid-19, make sure your activity meets two out of the following three conditions: outdoors, distanced and masked.Outdoors + Distanced = No Mask NeededOutdoors + No Distance = Mask NeededNot Outdoors + Distanced = Mask NeededWhen masks are needed outdoorsIf you stop to have an extended conversation with someone who isn’t vaccinated, masks are recommended. Even outdoors, your risk of breathing someone else’s air increases the longer and closer you stand to them. One of the few documented cases of outdoor transmission happened in China early in the pandemic, when a 27-year-old man stopped to chat outside with a friend who had just returned from Wuhan, where the virus originated. Seven days later, he had his first symptoms of Covid-19.And masks are still advised if you find yourself in an outdoor crowd. Standing shoulder to shoulder with strangers during an outdoor concert or a protest could increase risk, particularly for the unvaccinated.Recently while hiking without a mask, Dr. Marr said she still made an effort to keep her distance from large groups when the trail got crowded.“If I was passing by a solo hiker it didn’t concern me,” said Dr. Marr. “But if I passed by a group of 10 hikers in a row, I stepped further off the path. The risk is still low, but at some point there could be a large enough pack of people that the risk could become appreciable.”When outdoor risk is lowestWalking your dog, riding a bike, hiking on a trail or picnicking with members of your household or vaccinated friends are all activities where the risk for virus exposure is negligible. In these kinds of situations, you can keep a mask on hand in your pocket, in case you find yourself in a crowd or need to go indoors..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-rqynmc{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.9375rem;line-height:1.25rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-rqynmc{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-rqynmc strong{font-weight:600;}.css-rqynmc em{font-style:italic;}.css-yoay6m{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}@media (min-width:740px){.css-yoay6m{font-size:1.25rem;line-height:1.4375rem;}}.css-1dg6kl4{margin-top:5px;margin-bottom:15px;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}#masthead-bar-one{display:none;}#masthead-bar-one{display:none;}.css-1pd7fgo{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-1pd7fgo{padding:20px;width:100%;}}.css-1pd7fgo:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1pd7fgo{border:none;padding:20px 0 0;border-top:1px solid #121212;}.css-1pd7fgo[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-1pd7fgo[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-1pd7fgo[data-truncated] .css-5gimkt:after{content:’See more’;}.css-1pd7fgo[data-truncated] .css-6mllg9{opacity:1;}.css-1rh1sk1{margin:0 auto;overflow:hidden;}.css-1rh1sk1 strong{font-weight:700;}.css-1rh1sk1 em{font-style:italic;}.css-1rh1sk1 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#ccd9e3;text-decoration-color:#ccd9e3;}.css-1rh1sk1 a:visited{color:#333;-webkit-text-decoration-color:#ccc;text-decoration-color:#ccc;}.css-1rh1sk1 a:hover{-webkit-text-decoration:none;text-decoration:none;}“I think it’s a bit too much to ask people to put the mask on when they go out for a walk or jogging or cycling,” said Dr. Muge Cevik, a clinical lecturer of infectious disease and medical virology at the University of St. Andrews School of Medicine in Scotland, where outdoor masking has never been required. “We’re in a different stage of the pandemic. I think outdoor masks should not have been mandated at all. It’s not where the infection and transmission occurs.”“Let me go for my run, maskless. Mask in pocket,” tweeted Dr. Nahid Bhadelia, an infectious diseases physician and the medical director of the special pathogens unit at Boston Medical Center. “Given how conservative I have been on my opinions all year, this should tell you how low risk is, in general, for outdoors transmission for contact over short periods — and lower still after vaccination. Keep the masks on you for when you are stationary in a crowd and headed indoors.”To understand just how low the risk of outdoor transmission is, researchers in Italy used mathematical models to calculate the amount of time it would take for a person to become infected outdoors in Milan. They imagined a grim scenario in which 10 percent of the population was infected with Covid-19. Their calculations showed that if a person avoided crowds, it would take, on average, 31.5 days of continuous outdoor exposure to inhale a dose of virus sufficient to transmit infection.“The results are that this risk is negligible in outdoor air if crowds and direct contact among people are avoided,” said Daniele Contini, senior author of the study and an aerosol scientist at the Institute of Atmospheric Sciences and Climate in Lecce, Italy.Even as more-infectious virus variants circulate, the physics of viral transmission outdoors haven’t changed, and the risk of getting infected outdoors is still low, say virus experts. Pay attention to the rates of infection in your community. If case counts are surging, your risk of encountering an infected person goes up.When outdoor fun moves indoorsDr. Cevik notes that debates about outdoor masking and articles showing photos of crowded beaches during the pandemic have left people with the wrong impression that parks and beaches are unsafe, and distracted from the much higher risks of indoor transmission. Often it’s the indoor activities associated with outdoor fun — like traveling unmasked in a subway or car to go hiking, or dropping into a pub after spending time at the beach — that pose the highest risk. “People hold barbecues outdoors, but then they spend time indoors chatting in the kitchen,” said Dr. Cevik.As more people get vaccinated, decisions about going maskless outdoors will get easier. While no vaccine offers 100 percent protection, the rate of breakthrough infections so far has been exceedingly low. The U.S. Centers for Disease Control and Prevention recently reported just 5,800 cases of breakthrough infections among 75 million vaccinated people. And the C.D.C. has said vaccinated friends and family members can safely spend time together, without masks.But it’s OK to keep wearing your mask outdoors if you prefer it. After a year of taking pandemic precautions, it may be hard for people to adjust to less restrictive behaviors. Sarit A. Golub, a psychology professor at Hunter College of the City University of New York, said it’s important for both the media and public health officials to communicate the reasons people can modify some behaviors, like outdoor masking.“In the coming months, ‘normal life’ will begin to become safer, but I worry that some people won’t be willing or able to relax pandemic restrictions in ways that makes sense,” Dr. Golub said. “I worry that folks have internalized the fear messaging without understanding the reasons behind specific behavioral recommendations, and therefore, the reasons that they can be modified as circumstances change.”Gregg Gonsalves, assistant professor of epidemiology at the Yale School of Public Health, said he recently was with a group of parents, including many vaccinated physicians, who met in a New Haven park to celebrate a child’s first birthday. “We’re all just standing around, everybody was masked, and then we started asking, ‘When’s the time we can be outside and take off our masks?’” Dr. Gonsalves said. “If people are vaccinated and you’re outdoors, masks are probably superfluous at this point.”But Dr. Gonsalves said he understands why some people may be reluctant to give up their masks outdoors. “Some of this is Covid hangover,” he said. “We’ve been so traumatized by all of this. I think we need to have a little bit of compassion for the people having trouble letting go.”Illustrations by Eden Weingart

Vaccines do a good job of protecting us from coronavirus, but fear and confusion about the rise of variants have muddled the message. Here are answers to common questions.The news about coronavirus variants can sound like a horror movie, with references to a “double-mutant” virus, “vaccine-evading” variants and even an “Eek” mutation. One headline warned ominously: “The devil is already here.”While it’s true that the virus variants are a significant public health concern, the unrelenting focus on each new variant has created undue alarm and a false impression that vaccines don’t protect us against the various variants that continue to emerge.“I use the term ‘scariants,’” said Dr. Eric Topol, professor of molecular medicine at Scripps Research in La Jolla, Calif., referring to much of the media coverage of the variants. “Even my wife was saying, ‘What about this double mutant?’ It drives me nuts. People are scared unnecessarily. If you’re fully vaccinated, two weeks post dose, you shouldn’t have to worry about variants at all.”Viruses are constantly changing, and new variants have been emerging and circulating around the world throughout the pandemic. Some mutations don’t matter, but others can make things much worse by creating a variant that spreads faster or makes people sicker. While the rise of more infectious variants has caused cases of Covid-19 to surge around the world, the risk is primarily to the unvaccinated, for whom there is great concern. While vaccination efforts are well underway in the United States and many other developed countries, huge swaths of the world’s population remain vulnerable, with some countries yet to report having administered a single dose.But for the vaccinated, the outlook is much more hopeful. While it’s true that the vaccines have different success rates against different variants, the perception that they don’t work against variants at all is incorrect. In fact, the available vaccines have worked remarkably well so far, not just at preventing infection but, most important, at preventing serious illness and hospitalization, even as new variants circulate around the globe.The variants are “all the more reason to get vaccinated,” said Dr. Anthony S. Fauci, the nation’s top infectious disease specialist. “The bottom line is the vaccines we are using very well protect against the most dominant variant we have right now, and to varying degrees protect against serious disease among several of the other variants.”Part of the confusion stems from what vaccine efficacy really means and the use of terms like “vaccine evasion,” which sounds a lot scarier than it is. In addition, the fact that two vaccines have achieved about 95 percent efficacy has created unrealistic expectations about what it takes for a vaccine to perform well. Here are answers to common questions about the variants and the vaccines being used to stop Covid-19.Which variant am I most likely to encounter in the United States?The variant called B.1.1.7, which was first identified in Britain, is now the most common source of new infections in the United States. This highly contagious variant is also fueling the spread of the virus in Europe and has been found in 114 countries. A mutation allows this version of the virus to more effectively attach to cells. Carriers may also shed much higher levels of virus and stay infectious longer.The main concern about B.1.1.7 is that it is highly infectious and spreads quickly among the unvaccinated, potentially overwhelming hospitals in areas where cases are surging.Do the vaccines work against B.1.1.7?All of the major vaccines in use — Pfizer-BioNTech, Moderna, Johnson & Johnson, AstraZeneca, Sputnik and Novavax — have been shown to be effective against B.1.1.7. We know this from a variety of studies and indicators. First, scientists have used the blood of vaccinated patients to study how well vaccine antibodies bind to a variant in a test tube. The vaccines have all performed relatively well against B.1.1.7. There’s also clinical trial data, particularly from Johnson & Johnson and AstraZeneca (which is the most widely used vaccine around the world), that shows they are highly effective against both preventing infection and serious illness in areas where B.1.1.7 is circulating. And in Israel, for instance, where 80 percent of the eligible population is vaccinated (all with the Pfizer shot), case counts are plummeting, even as schools, restaurants and workplaces open up, suggesting that vaccines are tamping down new infections, including those caused by variants.If the vaccines are working, why do I keep hearing about “breakthrough” cases?No vaccine is foolproof, and even though the Covid vaccines are highly protective, sometimes vaccinated people still get infected. But breakthrough cases of vaccinated people are very rare, even as variants are fueling a surge in case counts. And the vaccines clearly prevent severe illness and hospitalization in the few vaccinated patients who do get infected.So what’s the risk of getting infected after vaccination? Nobody knows for sure, but we have some clues. During the Moderna trial, for instance, only 11 patients out of 15,210 who were vaccinated got infected. Both Pfizer and Moderna now are doing more detailed studies of breakthrough cases among vaccinated trial participants, and should be releasing that data soon.Two real-world studies of vaccinated health care workers, who have a much higher risk of virus exposure than the rest of us, offer hopeful signs. One study found that just four out of 8,121 fully vaccinated employees at the University of Texas Southwestern Medical Center in Dallas became infected. The other found that only seven out of 14,990 workers at UC San Diego Health and the David Geffen School of Medicine at the University of California, Los Angeles, tested positive two or more weeks after receiving a second dose of either the Pfizer-BioNTech or Moderna vaccines. Both reports were published in the New England Journal of Medicine, and are a sign that even as cases were surging in the United States, breakthrough cases were uncommon, even among individuals who were often exposed to sick patients. Most important, patients who were infected after vaccination had mild symptoms. Some people had no symptoms at all, and were discovered only through testing in studies or as part of their unrelated medical care.Researchers are still studying whether the variants eventually might increase the number of breakthrough cases or if vaccine antibodies begin to wane over time. So far, data from Moderna show the vaccine still remains 90 percent effective after at least six months. Pfizer has reported similar results. A recent study of 149 people in Israel who became infected after vaccination with the Pfizer vaccine suggested that a variant first identified in South Africa was more likely to cause breakthrough infections. However, those eight infections occurred between days seven and 13 following the second dose. “We didn’t see any South Africa variant 14 days after the second dose,” said Adi Stern, the study’s senior author, a professor at the Shmunis School of Biomedicine and Cancer Research, Tel Aviv University. “It was a small sample size, but it’s very possible that two weeks after the second dose, maybe the protection level goes up and that blocks the South Africa variant completely. It gives us more room for optimism.”For now, the variants don’t appear to be increasing the rate of infection in vaccinated people, but that could change as more data are collected. Read more about breakthrough cases here.Are there other variants we should be worried about?The C.D.C. is tracking more than a dozen variants, but only a few qualify as “variants of concern,” which is a public health designation to identify variants that could be more transmissible or have other qualities that make them more of a risk. The main additional variants everyone is talking about right now are the B.1.351, which was first detected in South Africa, and the P.1, which was first identified in Brazil. While there are other variants (including two “California” variants, B.1.427 and B.1.429, and a New York variant, B.1.526) for now, it seems, that the South Africa and Brazil variants (which as of late March together accounted for about 2 percent of cases in the United States) are causing the most concern. While a new variant can emerge at any time, existing variants also compete with each other for dominance. One interesting new development: In countries like the United States where B.1.1.7 is dominant, some of the other variants seem to be getting crowded out, making them less of a worry.Is it true that the variants first identified in South Africa and Brazil can “evade” the vaccines?There is a concern that the B.1.351 and the P.1 are better at dodging vaccine antibodies than other variants. But that doesn’t mean the vaccines don’t work at all. It just means the level of protection you get from the vaccines against these variants could be lower than when the shots were studied against early forms of the virus. Among the variants, the B.1.351 may pose the biggest challenge so far. It has a key mutation — called E484K, and often shortened to “Eek” — that can help the virus evade some, but probably not all, antibodies.Remember that there’s a lot of “cushion” provided by this current crop of vaccines, so even if a vaccine is less effective against a variant, it appears that it’s still going to do a good job of protecting you from serious illness.How much protection will the vaccines give me against the variant first seen in South Africa?We don’t yet have precise estimates of vaccine effectiveness against B.1.351, which may be the most challenging variant so far. But studies show that the various vaccines still lower overall risk for infection and help prevent severe disease. A large study of Johnson & Johnson’s one-dose vaccine in South Africa found it was about 85 percent effective at preventing severe disease, and lowered risk for mild to moderate disease by 64 percent. (Distribution of the Johnson & Johnson vaccine has been paused as health officials investigate safety concerns.) There’s less definitive research for the Pfizer and Moderna vaccines against the variant, but it’s believed that these two-dose vaccines still reduce risk of infection against the variant by about 60 percent to 70 percent and still are highly effective at preventing severe disease and hospitalization..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-rqynmc{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.9375rem;line-height:1.25rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-rqynmc{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-rqynmc strong{font-weight:600;}.css-rqynmc em{font-style:italic;}.css-yoay6m{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}@media (min-width:740px){.css-yoay6m{font-size:1.25rem;line-height:1.4375rem;}}.css-1dg6kl4{margin-top:5px;margin-bottom:15px;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}#masthead-bar-one{display:none;}#masthead-bar-one{display:none;}.css-1pd7fgo{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-1pd7fgo{padding:20px;width:100%;}}.css-1pd7fgo:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1pd7fgo{border:none;padding:20px 0 0;border-top:1px solid #121212;}.css-1pd7fgo[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-1pd7fgo[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-1pd7fgo[data-truncated] .css-5gimkt:after{content:’See more’;}.css-1pd7fgo[data-truncated] .css-6mllg9{opacity:1;}.css-1rh1sk1{margin:0 auto;overflow:hidden;}.css-1rh1sk1 strong{font-weight:700;}.css-1rh1sk1 em{font-style:italic;}.css-1rh1sk1 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#ccd9e3;text-decoration-color:#ccd9e3;}.css-1rh1sk1 a:visited{color:#333;-webkit-text-decoration-color:#ccc;text-decoration-color:#ccc;}.css-1rh1sk1 a:hover{-webkit-text-decoration:none;text-decoration:none;}“From everything we know today, there is still protection from the vaccines against the South Africa variant,” said Dr. Stern.Should I still worry that the vaccines are less effective against some variants?Part of the problem is that we misinterpret what efficacy really means. When someone hears the term “70 percent efficacy,” for instance, they might wrongly conclude that it means 30 percent of vaccinated people would get sick. That’s not the case. Even if a vaccine loses some ground to a variant, a large portion of people are still protected, and only a fraction of vaccinated people will get infected. Here’s why.To understand efficacy, consider the data from the Pfizer clinical trials. In the unvaccinated group of 21,728, a total of 162 people got infected. But in the vaccinated group of 21,720, only eight people became infected. That’s what is referred to as 95 percent efficacy. It doesn’t mean that 5 percent of the participants (or 1,086 of them) got sick. It means 95 percent fewer vaccinated people got infected compared to the unvaccinated group.Now imagine a hypothetical scenario with a vaccine that is 70 percent effective against a more challenging variant. Under the same conditions of the clinical trial, vaccination would still protect 21,672 people in the group, and just 48 vaccinated people — less than one percent — would become infected, compared to 162 in the unvaccinated group. Even though overall efficacy was lower, only a fraction of vaccinated people in this scenario would get infected, most likely with only mild illness.While far more research is needed to fully understand how variants might dodge some (but not all) vaccine antibodies, public health experts note that an estimate of 50 percent to 70 percent efficacy against a challenging variant would still be considered an adequate level of protection.“Seventy percent is extremely high,” said Dr. Stern. “Basically what this means is that it’s even more important to get vaccinated. If you have 95 percent efficacy, you can create some form of herd immunity with less people. With 70 percent efficacy, it’s even more important to get vaccinated to protect others.”Am I going to need a booster shot?Vaccine makers already are working on developing booster shots that will target the variants, but it’s not clear how soon they might be needed. “In time, you’re going to see a recommendation for a booster,” said Dr. Peter J. Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston. “That booster will elevate everybody’s antibodies and increase durability. The booster will probably be configured to target the South African and Brazil variants.”Given all these unknowns about the variants, shouldn’t I just stay home even after I’m vaccinated?Even amid the rise of variants, vaccines will significantly lower your risk for infection and will protect you from serious illness and hospitalization.People who are vaccinated can socialize, unmasked, with other vaccinated people. While vaccinated people still need to follow local health guidelines about wearing a mask and gathering in groups to protect the unvaccinated, vaccinated people can travel, get their hair and nails done, or go to work without worrying. And vaccinated grandparents can hug their unvaccinated grandchildren. Because there are still some outstanding questions about the risk of vaccinated people carrying the virus, a vaccinated person is still advised to wear a mask in public to protect the unvaccinated — although those guidelines may be updated soon.“The vaccines protect you, so go get vaccinated — that’s the message,” said Dr. Fauci. “If you’re around other vaccinated people, you shouldn’t worry about it at all. Zero.”

The most common questions about vaccination side effects, answered.Every day nearly three million people in the United States are getting the Covid-19 vaccine. And every new jab prompts new questions about what to expect after vaccination.Last week I asked readers to send me their questions about vaccinations. Here are some answers.Q: I’ve heard the Covid vaccine side effects, especially after the second dose, can be really bad. Should I be worried?Short-lived side effects like fatigue, headache, muscle aches and fever are more common after the second dose of both the Pfizer-BioNTech and the Moderna vaccines, which each require two shots. (The Johnson & Johnson vaccine requires only a single shot.) Patients who experience unpleasant side effects after the second dose often describe feeling as if they have a bad flu and use phrases like “it flattened me” or “I was useless for two days.” During vaccine studies, patients were advised to schedule a few days off work after the second dose just in case they needed to spend a day or two in bed.Data collected from v-safe, the app everyone is encouraged to use to track side effects after vaccination, also show an increase in reported side effects after the second dose. For instance, about 29 percent of people reported fatigue after the first Pfizer-BioNTech shot, but that jumped to 50 percent after the second dose. Muscle pain rose from 17 percent after the first shot to 42 percent after the second. While only about 7 percent of people got chills and fever after the first dose, that increased to about 26 percent after the second dose.The New York Times interviewed several dozen of the newly vaccinated in the days afterward. They recounted a wide spectrum of responses, from no reaction at all to symptoms like uncontrolled shivering and “brain fog.” While these experiences aren’t pleasant, they are a sign that your own immune system is mounting a potent response to the vaccine.Q: Is it true that women are more likely to get worse side effects from the vaccine than men?An analysis of safety data from the first 13.7 million Covid-19 vaccine doses given to Americans found that side effects were more common in women. And while severe reactions to the Covid vaccine are rare, nearly all the cases of anaphylaxis, or life-threatening allergic reactions, occurred in women.The finding that women are more likely to report and experience unpleasant side effects to the Covid vaccine is consistent with other vaccines as well. Women and girls can produce up to twice as many antibodies after receiving flu shots and vaccines for measles, mumps and rubella (M.M.R.) and hepatitis A and B. One study found that over nearly three decades, women accounted for 80 percent of all adult anaphylactic reactions to vaccines.While it’s true that women may be more likely to report side effects than men, the higher rate of side effects in women also has a biological explanation. Estrogen can stimulate an immune response, whereas testosterone can blunt it. In addition, many immune-related genes are on the X chromosome, of which women have two copies and men have only one. These robust immune responses help to explain why 80 percent of autoimmune diseases afflict women. You can read more about women and vaccine side effects here.Q: I didn’t have any side effects. Does that mean my immune system didn’t respond and the vaccine isn’t working?Side effects get all the attention, but if you look at the data from vaccine clinical trials and the real world, you’ll see that many people don’t experience any side effects beyond a sore arm. In the Pfizer vaccine trials, about one out of four patients reported no side effects. In the Moderna trials, 57 percent of patients (64 or younger) reported side effects after the first dose — that jumped to 82 percent after the second dose, which means almost one in five patients reported no reaction after the second shot.A lack of side effects does not mean the vaccine isn’t working, said Dr. Paul Offit, a professor at the University of Pennsylvania and a member of the Food and Drug Administration’s vaccine advisory panel. Dr. Offit noted that during the vaccine trials, a significant number of people didn’t report side effects, and yet the trials showed that about 95 percent of people were protected. “That proves you don’t have to have side effects in order to be protected,” he said.Nobody really knows why some people have a lot of side effects and others have none. We do know that younger people mount stronger immune responses to vaccines than older people, whose immune systems get weaker with age. Women typically have stronger immune responses than men. But again, these differences don’t mean that you aren’t protected if you don’t feel much after getting the shot.Scientists still aren’t sure how effective the vaccines are in people whose immune systems may be weakened from certain medical conditions, such as cancer treatments or H.I.V. infection or because they are taking immune suppressing drugs. But most experts believe the vaccines still offer these patients some protection against Covid-19.The bottom line is that even though individual immune responses can vary, the data collected so far show that all three vaccines approved in the United States — Pfizer-BioNTech, Moderna and Johnson & Johnson — are effective against severe illness and death from Covid-19.Q: I took Tylenol before I had my Covid vaccine shots and had very little reaction to the shots. Did I make a big mistake?You shouldn’t try to stave off discomfort by taking a pain reliever before getting the shot. The concern is that premedicating with a pain reliever like acetaminophen (Tylenol) or ibuprofen (Advil, Motrin), which can prevent side effects like arm soreness as well as fever or headache, might also blunt your body’s immune response.While it’s possible that taking a pain reliever before your shots might have dampened your body’s immune response, vaccine experts say you shouldn’t worry, and you shouldn’t try to get another shot. Studies of other vaccines suggest that while premedicating can dull the body’s immune response to a vaccine, your immune system can still mount a strong enough defense to fight infection. A review of studies of more than 5,000 children compared antibody levels in children who took pain relievers before and after vaccinations and those who did not. They found that pain relievers did not have a meaningful impact on immune response, and that children in both groups generated adequate levels of antibodies after their shots.The high efficacy of all the Covid vaccines suggests that even if taking Tylenol before the shot did blunt your body’s immune response, there’s some wiggle room, and you are likely still well protected against Covid-19. “You should feel reassured that you’ll have enough of an immune response that you’ll will be protected, especially for vaccines that are this good,” said Dr. Offit.Q: What about taking a pain reliever after the shot?“It’s OK to treat” side effects with a pain reliever, said Dr. Offit, but if you don’t really need one, “don’t take it.”While most experts agree it’s safe to take a pain reliever to relieve discomfort after you get vaccinated, they advise against taking it after the shot as a preventive or if your symptoms are manageable without it. The concern with taking an unnecessary pain reliever is that it could blunt some of the effects of the vaccine. (In terms of the vaccine, there’s no meaningful difference if you choose acetaminophen or ibuprofen.)During the Moderna trial, about 26 percent of people took acetaminophen to relieve side effects, and the overall efficacy of the vaccine still was 94 percent.Q: Are the side effects worse if you’ve already had Covid-19?Research and anecdotal reports suggest that people with a previously diagnosed Covid-19 infection may have a stronger reaction and more side effects after their first dose of vaccine compared to those who were never infected with the virus. A strong reaction to your first dose of vaccine also might be a sign that you were previously infected, even if you weren’t aware of it.If you previously tested positive for Covid-19 or had a positive antibody blood test, be prepared for a stronger reaction to your first dose, and consider scheduling a few days off work just in case. Not only will it be more comfortable to stay home and recover in bed, the vaccine side effects can resemble the symptoms Covid-19, and your co-workers won’t want to be near you anyway.Q: I had Covid-19 already. Does that mean I can just get one dose?Studies suggest that one dose might be adequate for people who have a previously confirmed case of Covid-19, but so far the medical guidelines haven’t changed. If you’ve received the Pfizer-BioNTech or Moderna vaccines, you should plan to get your second dose even if you’ve had Covid-19. Skipping your second dose could create problems if your employer or an airline ask to see proof of vaccination in the future. If you live in an area where the single-dose Johnson & Johnson vaccine is available, then you can be fully vaccinated after just one dose. You can read more here about the vaccine response in people who’ve had Covid-19.Q: Will the vaccines work against the new variants that have emerged around the world?The vaccines appear to be effective against a new variant that originated in Britain and is quickly becoming dominant in the United States. But some variants of the coronavirus, particularly one first identified in South Africa and one in Brazil, appear to be more adept at dodging antibodies in vaccinated people.While that sounds worrisome, there’s reason to be hopeful. Vaccinated people exposed to a more resistant variant still appear to be protected against serious illness. And scientists have a clear enough understanding of the variants that they already are working on developing booster shots that will target the variants. The variants identified in South Africa and Brazil are not yet widespread in the United States.People who are vaccinated should still wear masks in public and comply with public health guidelines, but you shouldn’t live in fear of variants, said Dr. Peter J. Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston. “If you’re vaccinated, you should feel pretty confident about how protected you are,” said Dr. Hotez. “It’s unlikely you’ll ever go to a hospital or an I.C.U. with Covid-19. In time you’re going to see a recommendation for a booster.”I hope these answers will reassure you about your own vaccine experience. You can find a more complete list of questions and answers in our special vaccine tool “Answers to All Your Questions About Getting Vaccinated Against Covid-19.”

Medical privacy has become the latest casualty of vaccination efforts, as friends, co-workers and even total strangers ask intrusive questions about personal health conditions.Peter GamlenWhen Helena Jenkins, 23, recently asked to leave work early for a vaccination appointment, her boss at a Nashville retail store was incredulous.“Well how did you get that?” he asked.Ms. Jenkins was embarrassed, but answered truthfully. “Um, my weight,” she stammered, referring to the fact that, in Tennessee, a body mass index of 30 qualified her for vaccination in early March. “I had a moment of ‘ugh,’” she said later. “It made me so uncomfortable, but it didn’t click until afterward that I definitely didn’t have to answer that.”As public health officials push to get more at-risk people vaccinated, many of the newly qualified are discovering an unwelcome side effect of vaccination: Intrusive questions about their personal health.The majority of states now have expanded vaccine eligibility to include people with underlying health conditions that put them at risk for complications from Covid-19, such as high blood pressure, a compromised immune system or obesity. As a result, the demographics of the vaccine waiting lines have shifted from mostly older people and now include many seemingly healthy people in their 20s, 30s and 40s. Young vaccine recipients say their friends and co-workers are intensely curious about the appointment process, and as a result, often ignore boundaries about personal health that they never would have crossed in the past. Some of them ask directly: “What health problem allowed you to qualify?”When Amy Coody, 43, a mental health worker in Montgomery, Ala., told her friends and colleagues she had a vaccine appointment, she was shocked when it felt like people were judging her and assuming she had taken another person’s spot in line. Ms. Coody knows that she looks young and healthy, but she qualifies for two reasons — her work takes her into hospital settings, and she also has an underlying health condition that puts her at high risk.“The hostility was definitely there,” she said. “They’d be like, ‘Wait, how did you get an appointment?’ I wasn’t prepared for that kind of reaction. It took me off guard so I eventually stopped telling people I planned to get the vaccine.”Vaccine supply issues resulted in the cancellation of two of her appointments, and the shaming even made her debate rescheduling. “I would never want to step in front of somebody who needed it,” said Ms. Coody. “Then I realized, I do need it. There are a lot of patients in hospitals waiting for care. I thought, it’s about them. It’s not about me and my shame or anybody else who doesn’t understand the situation.”Getting policed about a hidden health issue isn’t new to Ms. Coody, who has a condition called dysautonomia, a disorder of the autonomic nervous system that can cause her to suddenly pass out. She said the vaccine shaming she has experienced was similar to when she’s been confronted after parking in a handicapped space, even though she has a tag that allows her to park there.“People come up to me and say, ‘You’re young and you obviously don’t have an illness so why are you taking a handicap spot?’” Ms. Coody said. “Even though it’s none of their business, I feel the need to defend myself. If more people realized there are invisible illnesses out there, maybe they might be a little more respectful about it.”Even total strangers waiting in vaccine lines have felt justified in interrogating someone who looks young and healthy. Those on the receiving end of the questions say the implication is that they must have cheated and jumped the line.Joanna Hua, 23 and a graduate student at Georgetown University, was standing in line for her second dose recently when an older woman she’d never met confronted her. “She looked at me and said, ‘You look very young to be getting the vaccine,’” Ms. Hua recounted. “She asked me, ‘How did you end up being able to qualify for one?’”Ms. Hua said she was taken aback by the question. She told the woman truthfully that she qualified because she worked in a grocery store, but she didn’t mention that she also qualified based on her weight. She said another young woman in line near her also nervously explained her reasons for qualifying.“I felt an instinctive need to justify myself,” said Ms. Hua. “It felt almost accusatory and invasive to ask about it. I think there is some sort of idea going around that people are just taking advantage and trying to get a vaccine whenever possible. I don’t doubt that some people do that. But to have a stranger come up and ask you?”Tanmoy Lala Das, a medical and doctoral student in New York City, has been helping with vaccination efforts in Manhattan, giving shots to patients and helping as a patient navigator. He said overall the experience at vaccination centers has been upbeat, and everyone is collegial and happy to be there. But he has, on occasion, heard people asking others about personal health issues while waiting in line for their shots.“I’ve overheard people ask, ‘So what brings you in today?’” Mr. Das said. “The less stigmatized conditions people are open to talking about. They’d laugh and say, “Oh, you know, diabetes.’ I think the ones who are more sensitive, they say, ‘Oh, I just got a spot.’”It doesn’t help that many people know someone who has jumped the line by claiming to be a teacher or a smoker or lying about a health condition. In New York a fitness instructor got vaccinated by claiming to be an educator, and in Florida two women even “dressed up as grannies” to get the vaccine.“I think in New York, people are trying to figure out these dynamics of are you getting the dose because it was left over, or a condition that qualifies you or did you lie about something,” said Mr. Das. “The honest reality is I know people who have cut the line and lied about things — 29-year-old people who have gotten vaccines who don’t have pre-existing conditions. But I think most people are not lying. The goal is to vaccinate everyone.”Rhonda Wolfson, who lives in Toronto, said that in places where the vaccination process still is age-restricted, it has created a different privacy problem, casting light on the fact that a person is above a certain age. Ms. Wolfson qualified for a pilot vaccination program in Ontario for people aged 60 to 64, and she realized that talking about her vaccination would reveal her as a sexagenarian to people who thought she was younger.“I have one friend in her 40s, and she knows I’m older, but she doesn’t know my exact age,” said Ms. Wolfson. “She’s never asked, and I’ve never offered. I spoke to her last week and in my excitement I mentioned, ‘OMG, I got vaccinated.’ I could almost hear her pause, ‘Oh, you’re that age.’”In some circles, the stigma of early vaccination is even more concerning because it could dissuade at-risk people from getting the shot. In the gay community, for instance, a young person who gets vaccinated in the early group might be seen to be immunocompromised.“In the gay community there is this assumption that if you are getting the vaccine right now you must be secretly H.I.V. positive,” said Mr. Das, who is gay. “It has become an assumption in the community that if you’re a gay and you post a picture of the vaccine card, you’re positive and haven’t told us. I always talk to my friends and tell them, ‘Don’t assume things.’”Mr. Das said he is hopeful that any stigma or medical privacy issues associated with early vaccination will disappear once vaccine appointments are open to everyone. President Biden has urged all states to expand medical eligibility to the general population by May 1, and many states, including Alaska, Arizona, Georgia and Mississippi, have already made the change.“The sooner we get to vaccinating everyone, I think this question of ‘Oh, what qualified you?’ will stop,” Mr. Das said. “Once that goes away hopefully these barriers will break down, and people won’t keep asking these very personal questions.”