What You Can Do Post-Vaccine, and When

Vaccines are here, bringing hope of the pandemic’s end. But even when you get your dose, it won’t mean an immediate return to life as you knew it.

Scientists cite several reasons for staying masked and cautious as you start your post-vaccine life. Vaccines don’t offer perfect protection; we don’t yet know whether vaccinated people can spread the virus; and coronavirus is likely to continue its rapid spread until a large majority of the population is vaccinated or has survived a natural infection.

Because vaccines will not be a ticket back to 2019, Uma Karmarkar, a neuroeconomist at the University of California, San Diego, recommends that people think about “how we are moving forward” instead of “getting back to normal.” (Neuroeconomics bridges neuroscience, psychology and economics.)

Vaccination provides you and society the best way to move forward. Some parts of life will begin to feel different as soon as the vaccine kicks in. Other changes will take longer. When it comes to thinking about what’s safe, it may help to think of post-vaccine life in several phases.

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. But vaccinated people should still wear masks and avoid large groups and indoor gatherings.

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 U.S. 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 percent of the population was vaccinated.

Kelsey Vandersteen, a trauma I.C.U. nurse at UW Health University Hospital in Madison, Wis., 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 have loved ones who will be vaccinated before they are, such as those who are at high risk because of their age or underlying conditions. Socializing with them before you are vaccinated is a harder question, experts said. It would certainly be safer than it is now, but the small chance of infecting someone who is at high risk may not be worth it.

Other people will be vaccinated early because their jobs leave them highly exposed to the virus; it will continue to be risky to spend time with them before you also have immunity, experts said.

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. 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’s ability to spread.

When a large majority of people are vaccinated, scientists said, it will be safer to do things in your community, like eat at indoor restaurants, attend a party or ride a bus. Next Christmas, families can probably gather in ways they should avoid this year, they said.

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 over all. 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’s 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, Professor 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 coming 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.

“It’s a really exciting time for science, but I would maintain that caution,” said Delivette Castor, an infectious disease epidemiologist at Columbia. “For me personally, I will not be at ease until we have sufficient coverage in the community and we’ve had it for a durable period of time.”

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, Professor Castor said. These include methods for tracking emerging infections and screening before activities like flying.