En español | When can we all get back to normal?
As the COVID-19 vaccination rollout gains speed, that's the question on the mind of many Americans. Unfortunately, the answer is less than clear-cut.
Experts say we first need to reach “herd immunity,” which is achieved when a significant proportion of the population becomes immune, mostly through vaccination, so the coronavirus can no longer spread easily.
White House chief medical adviser Anthony Fauci has estimated that 70 to 85 percent of the U.S. population needs to be vaccinated to develop “a blanket of protection over the country and very little viral activity.”
Monica Gandhi, M.D., an infectious disease doctor and professor of medicine at the University of California, San Francisco, says we will know we're on the road to normalcy based on what's happening in hospitals and in the community.
"We will know it when we see it,” she says. “First, hospitalizations will be massively reduced, because people can't get severe disease after they're immunized. Second, cases will be so low that even when people [have respiratory symptoms and] test, they won't have it.”
Estimates of when we will reach that point are all over the map. Some experts predict a return to normalcy as soon as April or May, while others say it may not be until 2022.
The wide discrepancy reflects the reality that a range of complex factors could affect the timeline, in ways both good and bad. Here are four of the biggest variables that will determine when we can return to some semblance of normalcy.
1. The pace of vaccination
Probably the most important factor is the speed of the vaccine rollout. If the U.S. administers 1.9 million doses a day — the average vaccination rate in early March — it would take an estimated seven months to cover 75 percent of the U.S. population with a two-dose vaccine, according to a Bloomberg projection.
But it likely won't take that long, experts say, because vaccine makers are ramping up production, with the potential to significantly boost the number of vaccinations administered per day. President Joe Biden announced March 2 that he expected there would be enough doses of coronavirus vaccine available for the entire U.S. adult population by the end of May, though he says it will take longer to get all those shots in arms.
"We're moving in the right direction, but if you map out estimates of when we vaccinate enough people [for a return to normalcy], we're still well into the summer,” says Cameron Wolfe, MBBS, an infectious disease specialist and co-chair of the clinical COVID-19 task force at the Duke University Medical School in Durham, North Carolina.
The other question mark is when we'll have a vaccine that's approved for children, says Christopher Murray, M.D., director of the Institute for Health Metrics and Evaluation at the University of Washington in Seattle. The Pfizer-BioNTech vaccine is authorized for use in people 16 and older, while vaccines from Moderna and Johnson & Johnson are authorized for adults 18 and older. Although testing in children has started, health officials anticipate the vaccines may not be available to them until late 2021 or 2022.
Children “are a quarter of the population,” Murray points out. To reach herd immunity, Murray believes, “we first need to get a vaccine for kids, and then have close to 80 percent of kids and adults be vaccinated."
2. How long natural immunity lasts
If you factor in Americans who have immunity from past coronavirus infections, the country could potentially reach herd immunity faster, some experts say.
Marty Makary, M.D., of the Johns Hopkins School of Medicine and Bloomberg School of Public Health in Baltimore, writing recently in the Wall Street Journal, estimated that about 55 percent of all Americans likely have some natural immunity. When you combine that with the pace of vaccinations, he predicted that coronavirus infections would drop to an extremely low level by this spring.
"As more people have been infected, most of whom have mild or no symptoms, there are fewer Americans left to be infected,” Makary wrote. “At the current trajectory, I expect COVID will be mostly gone by April, allowing Americans to resume normal life."
Others say that's too optimistic, noting that the number of Americans who have natural immunity may not be that high and that no one knows how long natural immunity lasts.
"There is data that indicates even if you've been infected, you can still be reinfected,” says Louis Mansky, Ph.D., director of the Institute for Molecular Virology at the University of Minnesota in Minneapolis. “The type of immunity that you get from an infection is not as good as what you get from the vaccine.”
3. More contagious virus variants
Mansky and Murray says they believe variants — new strains of the coronavirus that are more transmissible — are the biggest factor that could lengthen the time it takes to get us back to normal.
The current COVID-19 vaccines have been found to work against some variants, including B.1.1.7., the strain first found in the United Kingdom and that is now in at least 44 U.S. states. But a few, such as a variant first identified in South Africa, appear to have more ability to evade vaccine protection and natural immunity. Vaccine makers are working on boosters to protect against the strains.
Meanwhile, we are in a race, Mansky says, to vaccinate as many people as possible quickly, before the variants can take hold. That's also why it's so important to continue to take precautions like social distancing and wearing a mask, he added.
If the variants spread faster than vaccinations can occur, we face the possibility of a new surge in cases this spring, and that will make it a lot harder to reach herd immunity. Higher levels of herd immunity are needed with a more contagious variant, Murray says.
However, if we get through May and we haven't seen a spike, we will be “in much better shape to be on a more predictable trajectory toward normalcy,” Mansky says.
4. Vaccine hesitancy
Reaching herd immunity depends on a large proportion of Americans getting vaccinated. Surveys show the percentage willing to get a COVID-19 vaccine has gradually increased since last summer, but about 40 percent are still at least somewhat reluctant.
In a February Kaiser Family Foundation poll, 22 percent said they want to “wait and see” how the vaccine is working, 15 percent said they will definitely not get vaccinated, and 7 percent said they will get the vaccine “only if required for work, school, or other activities.”
Persuading those people to get vaccinated “will take a lot of public information campaigns and physicians telling their patients how important it is,” Murray says.
Other factors that have the potential to impact our quest for herd immunity include how effective the vaccines are at stopping the spread of infection (we still don't know) and how long vaccine-induced immunity will last.
"What we don't want is for it to take so long to vaccinate some people that those who get vaccinated early start losing their immunity by the time we start vaccinating the rest of the population,” Wolfe says.
New normal will likely include the coronavirus
Wolfe, Gandhi, Mansky and Murray are all hopeful that some semblance of regular life will resume for Americans in the fall of 2021 or by early 2022 at the latest.
But they emphasize that the coronavirus will never be totally eradicated. It's already spread too far, and it's changing too fast. Instead, they said, the goal of public health efforts is to make it a manageable virus, like the seasonal flu. The vaccines authorized for use in the U.S. have been shown to be highly effective at reducing the number of severe COVID-19 cases and hospitalizations.
Depending on how long immunity from the vaccines last, we may need to get a coronavirus shot every year, or once every three years.
"The coronavirus will be with us, but it will not be terrible,” Gandhi says. “What's important is that we don't want to get severe disease. The vaccines mean that we can defang the virus, taking it from causing severe disease to a virus that causes a cold.”
Michelle Crouch is a contributing writer who has covered health and personal finance for some of the nation's top consumer publications. Her work has appeared in Reader's Digest, Real Simple, Prevention, The Washington Post and The New York Times.