The first raft of stories in the wake of the acceleration of the COVID-19 vaccine rollout in the U.S. centered on all the things the newly vaccinated among us can and cannot do, as if we were working off a master list of approved activities.
Like so many things associated with this pandemic, the truth is nowhere near that clean. No such list exists, and even the Centers for Disease Control and Prevention (CDC) has only issued recommendations, not requirements. Community and regional medical metrics come into play, and politics will carry its own dark weight when it comes to local or statewide decisions in areas as critical as masking, capacity in buildings and restaurants and so on.
Even such basic concepts as risk are subject to variances of opinion, as I discovered while soliciting input from several medical experts across the country and abroad. And as there are no clinical trials to address many of these questions, scientists are left to provide their best recommendations based on their interpretation of risk tolerance, both at an individual and population level, and their scientific knowledge of the virus and its kinetics.
First, here’s where the experts agree: The levels of protection provided by all of the available vaccines in clinical trials were extraordinary when it came to preventing severe disease, hospitalization and death. While the new variants pose a threat, most of those interviewed believe that current vaccines should provide reasonable protection there, too.
“To date, based on the studies by Johnson & Johnson in South Africa and Brazil, the vaccines will likely prevent hospitalization and death caused by the variants,” Paul Offit, an internationally recognized expert in virology and immunology and director of the Vaccine Education Center, wrote in an e-mail.
This is not the same as saying that a safe haven has been established. Most experts concurred that although we’ve seen declines in new daily cases of coronavirus since early January, the U.S. is still experiencing high levels of transmission of the virus, with approximately 60,000 new cases reported daily and about 1,500 deaths every day. These remain very high numbers.
“Our return to normalcy will be in two phases and is driven by two factors: the level of virus transmission in our communities and the proportion of people fully vaccinated,” says William Moss, executive director of the International Vaccine Access Center and professor of infectious disease epidemiology at the Johns Hopkins Bloomberg School of Public Health. Because of the high levels of viral spread and the low proportion of U.S. citizens fully vaccinated, Moss says, things like masking, social distancing, hand washing and avoiding large crowds remain critically important.
Vaccination efforts across the country have ramped up significantly in recent weeks. Currently, in the U.S., 2.1 million people are being vaccinated daily. More than 93 million doses have been administered in total, with 18 percent of Americans having received one dose and 9 percent two doses. President Biden has said that coronavirus vaccine should be available to all U.S. adults by the end of May.
But the questions of mobility, interaction and risk assessment are thorny ones. The good news (and, for many, the best news) is a general consensus that vaccinated people should be able to get together with others who’ve also received the vaccine, ditching masks and distancing precautions. The risk of infecting one another in these so called “immunity bubbles” is pretty low; Anthony Fauci, the president’s chief medical officer, concurs that small, maskless social gatherings in the home of those who are “doubly vaccinated” should be fine. New CDC public health recommendations for fully vaccinated people published March 8 likewise allow for fully vaccinated people to visit with other vaccinated people in a private setting, unmasked, without distancing.
Beyond that, though, the line becomes harder to draw. Monica Gandhi, an infectious disease physician and professor of medicine at the University of California, San Francisco, argues that those who’ve been vaccinated “are protected from severe COVID-19 infection at this point, and should feel free to start engaging in activities that they miss.” Those, she says, include going to an indoor bar or restaurant and attending movies, albeit with masking and distancing protocols in place—a level of reengagement that few other experts are willing to encourage at this time. (The CDC’s updated recommendations state that while the risk of going to a gym or dining indoors at a restaurant is lower for fully vaccinated people, health precautions should still be taken given the higher risk in these settings.)
Gandhi also suggested that indoor weddings, church services and school classrooms, among others, should be in play, again with masking, distancing and ventilation needs duly observed. That, for some experts, is a threshold they’re reluctant to cross because of viral spread issues indoors. Paul Griffin, an infectious disease specialist at the University of Queensland in Brisbane, Australia, emphasizes the need to try to hold these larger events outside when possible, restrict anyone unwell from attending, maintain social distancing (perhaps by spacing chairs further apart) and provide good ventilation by opening windows when possible.
If cases are running high in the community and social distancing cannot be maintained, Griffin says he would recommend mask-wearing and limiting the number of attendees. Some experts go further, concurring with the CDC’s latest guidance, which advise against “medium-or large-sized gatherings, regardless of vaccination status. Says Moss, “The recommendations will loosen when we see further declines in cases, hospitalizations and deaths.”
The experts I consulted are dealing with incomplete information, of course. We all are. And one of the things we don’t yet know, but would love to learn, is how well these vaccines actually control the spread of the virus. The answer to that question may well shape the largest body of medical advice when it comes to those who’ve already received their shots.
While the vaccine protects an individual well from symptomatic COVID-19, we are not sure whether that person can still develop asymptomatic infection (and, theoretically, then unknowingly pass the disease on to others). “If we want to get on top of the pandemic,” says Griffin, “we still need to try and reduce the chance of the virus being spread…. If a proportion of people can stay away from venues where people have a high probability of interacting, for example people choosing takeaway food or working from home when they can, then the chance of the virus being transmitted is greatly reduced and the effect of the vaccine rollout will be increased.”
Early real-world data suggest that vaccines likely will help prevent this asymptomatic transmission of the virus, but the information’s incomplete. Non-peer-reviewed data from the Israeli Health Ministry and Pfizer demonstrated an 89 percent reduction in both symptomatic and asymptomatic infections following vaccination, although some scientists believe this finding may be overstated. A vaccine trial by Johnson & Johnson, meanwhile, found that its vaccines prevented asymptomatic infection in 74 percent of recipients.
Vaccinated healthcare workers in the U.K. showed an 86 percent decrease in asymptomatic infection versus those who were not vaccinated, and another preliminary study showed a fourfold reduction in viral load for infections occurring weeks after Pfizer’s first vaccine, which may equate with reduced infectiousness. Moderna’s vaccine data also hinted that it reduced asymptomatic infections. “It seems very likely that the vaccines in use will reduce transmission,” says Griffin, “but we don’t have good data on it to be able to say how much.”
Gandhi is among those who believe that returning to work in person, if other co-workers have been vaccinated, is “perfectly safe.” Griffin, meanwhile, cautions that even with outdoor events, “the risk is obviously not zero.” The use of basic mitigating strategies, experts agreed, is going to remain front and center of any loosening of community restrictions that might result in the mixed company of those who have and have not received vaccines.
Can vaccinated grandparents travel to visit family? “Vaccinated grandparents are completely safe from severe disease with COVID-19 with the vaccines, and should finally see their family again!” says Gandhi. Based on accumulating evidence showing that “vaccines prevent transmission,” she says, “If there are grandchildren in the household who are not vaccinated, the grandparents will not transmit virus to them.” The CDC agrees that fully vaccinated individuals (or grandparents) may gather with unvaccinated people from a single household in a private home, among those who are at “low risk for severe COVID-19 disease,” without masking or distancing indoors. If unvaccinated people come from several households, then the visit should occur outdoors (or in a well-ventilated space) with proper precautions.
Why have scientists been so cautious? Gandhi believes it is partly that the vaccines themselves appear almost too good to be true. “But they are honestly that good,” she added. “I think we should take the data as it comes and has been coming for vaccines reducing transmission, and modify our recommendations accordingly.” (Some other experts said they felt that grandparents should assess the risks versus benefits —and if they choose to travel, consider masking and distancing until cases decline further.)
The idea of travel, particularly air travel, remains problematic. While some authorities believe that once you’ve been vaccinated, such travel is relatively low-risk (assuming you maintain masking requirements), others are more cautious, suggesting that air travel should wait until greater herd immunity is achieved. At a CNN Global Town Hall, Fauci warned that vaccination should not be considered a “free pass to travel.” The CDC did not update its travel recommendations on March 8, and continue to advise that unnecessary travel be avoided.
And we don’t know about the connection between vaccination and long COVID. If those who’ve had their shots can still develop asymptomatic or mild disease, are they also susceptible to becoming one of the group known as long haulers, those who may carry the symptoms for many months after illness?
Early evidence is encouraging, but slim. At Yale University, Akiko Iwasaki tweeted recently about an informal survey of 473 long-COVID patients; among those who were two weeks past their first vaccination, 27 of the respondents said their prolonged symptoms were slightly better, while 14 percent said they were slightly worse. Says Griffin, “While there is limited if any data on this (subject) to date, given the fact that we know the vaccines are not only very safe but very effective at reducing symptomatic infection and particularly severe disease, it would seem highly plausible that the longer-term manifestations or long COVID, will also be reduced.”
In the end, the experts say, local conditions are going to matter tremendously. Their suggestion to the newly vaccinated: Include in your decision-making how high background rates of disease are in your community, what emerging variants may be circulating, any personal risk factors that may place you or others around you at greater risk, and the real, time-proven knowledge that vaccines are not bulletproof.
Beyond that, people will make their choices. “The only thing we can/should really do as scientists, in my opinion, is to provide people with some reasonable assessment of their risk given an exposure—but even this is very difficult to do in practice,” said Kate Grabowski, an infectious-disease epidemiologist at Johns Hopkins Bloomberg School of Public Health.
We will know more in a few months when vaccine studies looking at transmission conclude and more data emerge. In the meantime, every new vaccination gets us closer to herd immunity. “It will be low case numbers, complemented with rigorous contact tracing and high proportion of vaccinated individuals that will eventually get us to safety—and back to normal lives,” says Moss.
Finally, a personal note: As a higher-risk individual, I found being vaccinated an incredibly liberating feeling, a weight off my shoulders. At the vaccination center where I work, every time I vaccinate someone and hand them a Jolly Rancher lollipop, we smile and celebrate a genuinely momentous occasion. The development of highly effective vaccines in less than a year is one of the most remarkable medical feats of our time. Now, we just need to see it all the way through.
https://www.scientificamerican.com/article/so-what-can-people-actually-do-after-being-vaccinated/
