COVID-19 Vaccine: What you can do post-vaccine, and when

What’s safer to do once I’m vaccinated?

When people are fully vaccinated (a week or two after the second dose), but most others aren’t yet, their lives probably shouldn’t change very much, experts say. It will most likely be safer for them to do things like visit the grocery store or the post office. People who work in places that leave them highly exposed will significantly decrease their risk — which is why frontline workers are among the first to be eligible for the vaccine. But vaccinated people should still wear masks and avoid large groups and indoor gatherings when possible.

That’s important for both their health and the health of others, experts said. Scientists are waiting to learn if vaccinated people can spread the virus to others. (Early data on transmission seems promising, but vaccines are very unlikely to curb contagiousness entirely.) Also, while early evidence suggests that the first vaccines in the US reduce people’s risk of developing COVID-19 by around 95 percent, that still means a small fraction could get sick — and as long as the virus is as widespread as it is now, even that small share could be a big number.

“Five percent of a really high number is still a high number, and what you want is 5 percent of a relatively medium or low number,” said Dr. Ashish Jha, a physician and the dean of the School of Public Health at Brown.

In an informal survey of 700 epidemiologists by The New York Times, less than a third said they would change their behavior after they were vaccinated; half said they would wait until at least 70 percentof the population was vaccinated.

Kelsey Vandersteen, a trauma ICU nurse at UW Health University Hospital in Madison, Wisconsin, will receive her first injection on Wednesday — probably months ahead of her young daughters and husband, who works from home for a software company.

Even after her second shot, she doesn’t intend to change her behavior, including wearing a mask. She says she hopes this will model good behavior for others. Besides, she said: “I prefer the mask. It protects me from other stuff as well. We’ve been completely healthy — not a sniffle since March.”

What’s safer to do once my friends and family are vaccinated?

If you and the people you want to see are all vaccinated, it should be safer to socialize with them, including indoors, experts said. But being in large groups or traveling, when there’s no way to know if the people around you have been vaccinated, will remain risky, they said.

Eric Lofgren, an infectious disease epidemiologist at Washington State University, said at that point, he would restart in-person board game nights and one-on-one meetings with students, but he wouldn’t fly on vacation or go to a movie theater.

“Immunity is not an on/off switch; it’s a dial,” he said. “If you’re below herd immunity, the virus is still happily circulating in the population and there’s always a chance the vaccine isn’t working for you.”

In some ways, this may be the hardest phase of post-vaccine life to navigate. Deciding which risks to take will involve calculations that can prove exhausting, said Elizabeth Dorrance Hall, an assistant professor of communications at Michigan State University: “Our brains just get so tired of weighing each and every thing that we just run out of brain power on gradients.”

Many people will be vaccinated at a different time than their loved ones, such as those who are at high risk because of their age or underlying conditions or whose jobs leave them highly exposed to the virus. Socializing before everyone in the group is vaccinated is a harder question, experts said. It would certainly be safer than it is now, but spread is possible before everyone has immunity, and people will still need to consider the small chance of infecting someone who is at high risk.

What’s safer to do once most of the population is vaccinated?

It should be much safer to move around once your community achieves herd immunity — the point when the virus can’t easily spread because enough people have become vaccinated or have already had the illness. This also helps protect people who can’t get vaccinated for health reasons, and people who work in crowded or indoor places. Many scientists think at least 70 percent of people need to have acquired immunity for the whole community to be protected. That number is just an estimate, though, and might need to be revised once we know more about how vaccines affect the virus’ ability to spread.

It’s too early to know exactly when we’ll hit that threshold. Although federal officials have said the United States should have the resources to vaccinate hundreds of millions of people by summer, many scientists say that timeline is optimistic. There could be logistical challenges to vaccinating everyone, and some people have expressed hesitancy about getting the vaccine.

It’s likely that some regions will have higher vaccination rates than others. Just as some communities have found themselves vulnerable to measles because of low childhood vaccination rates, areas with low COVID-19 vaccination rates may see outbreaks even if the country has reached a herd immunity level overall. Knowing that context will be crucial for decision making.

Also, experts stressed that even when herd immunity is reached, COVID-19 is not likely to disappear outright. Outbreaks could still be likely, probably in winter.

“Winter is going to start being flu and COVID season,” said Andrew Noymer, an epidemiologist studying COVID-19 at the University of California, Irvine. The last things he will return to, he said, are international travel and crowded events like concerts — but he expects to do those again at some point. He is waiting not just for the vaccine, but also for the virus’ spread to decrease greatly and for hospitals to have more capacity: “I intend to go back bit by bit.”

Why do we still need a risk budget after vaccines?

During the pandemic, experts have asked people to think of themselves as having a risk budget: If you spend some of that limited supply by engaging in riskier behaviors, you will need to cut back in other aspects of your life. Vaccines can expand an individual’s risk budget, Lofgren said. But they do not make the budget infinite: If you travel to see friends, you might still want to offset that decision by avoiding indoor restaurants.

The most effective route to more freedom is for as many people as possible to be vaccinated, experts say. Even though risks will remain, vaccines with 95 percent efficacy will be especially powerful once the number of coronavirus cases diminishes.

“The take-home to me is nothing is 100 percent, but it’s very good,” said Gypsyamber D’Souza, a professor of epidemiology at Johns Hopkins University.

It may be frustrating to keep waiting, but as people get extra protection from the vaccine, the daily decisions will get easier as everyone’s risk budget balloons.

What will the new normal look like?

Scientists said they were waiting to learn many things before they would feel comfortable doing more high-risk activities, like how many people wind up being vaccinated, how long immunity lasts (after vaccination and after infection) and whether the virus evolves.

This summer will probably be more open because more people will be vaccinated, and the virus seems to slow in warmer months as people can more easily socialize outdoors. But expect an uptick in cases and hospitalizations next winter, scientists say.

Scientists also say it’s unlikely that life will look exactly like 2019 again. In the new normal, there may be more mask-wearing during flu season or in crowded places because awareness has been raised. And there will probably be more systems in place to prevent pandemics from being as deadly, Castor said. These include methods for tracking emerging infections and screening before activities like flying.

That is a hopeful development, experts say. This year, rates of seasonal flu are substantially lower than usual, a shift they say is partly explained by the widespread use of masks and physical distancing. If we keep them up, the changes that coronavirus has wrought — like the decline of handshaking — may have payoffs in reducing risks of other diseases in the future.

c.2020 The New York Times Company