At the start of the pandemic, recovery from a coronavirus infection was perhaps a reason for cautious optimism: If you were lucky enough to bounce back from Covid-19, you had some level of immunity. Over time, research bore this out, though it also showed that immunity wanes, so recovering from the virus wasn’t a one-and-done deal. So how should vaccinated people think about their immunity after they’ve recovered from a breakthrough infection?
After an omicron surge that infected hundreds of thousands of people a day in the US — including many people who had breakthrough cases — some are wondering if the combination of vaccination and infection, known as hybrid immunity, will offer some kind of lasting protection. Is this brush with the virus enough to warrant relief and a resumption of life sans pandemic precautions? Vox spoke with experts to help advise the newly recovered.
What does a Covid-19 infection do for my immunity?
Immunity is defined as your body’s ability to protect you from getting sick when you’re exposed to bacteria, viruses, parasites, or fungi; immunity can help protect you from getting infected in the first place, and if you do get infected, it can prevent you from feeling ill or protect you from severe symptoms. Depending on the type of infection, this kind of protection can last for months, years, or even a lifetime. For instance, once people recover from measles, they’re immune for life and won’t catch it again. But most illnesses aren’t one and done. Immunity to Covid-19 can last for months, but it gets weaker over time and the exact duration is still being studied.
Everyone’s body and immune system react differently to the viruses they encounter. Unlike vaccines, which deliver a standard size and formula to large populations, “having a Covid infection is a very unstandardized thing,” says Theodore Bailey, the chief of the division of infectious diseases at the Greater Baltimore Medical Center. (Even though everyone’s immune system reacts differently to the same vaccine dose — someone could have serious side effects and others could have none — the shots themselves are standardized.)
If you tested positive for Covid-19, it’s difficult to know how much virus you were exposed to, how much it managed to reproduce in your body, and how engaged your immune system became to fight it off. So it’s hard to know how protected you will be, too. “One person’s infection is not someone else’s infection,” Bailey says.
Studies show that before omicron came along, recovery from Covid-19 infections made people a lot less likely to get infected again — at least for many months. But omicron seemed to behave differently: A non-peer-reviewed study conducted during England’s omicron wave found that omicron has the potential to evade immunity from past infection or two vaccine doses. Similarly, another non-peer-reviewed Danish study found that omicron was able to evade immune responses in vaccinated and unvaccinated people alike (though a small South African study showed an omicron infection may protect against delta, which now comprises a small minority of cases in the US).
For vaccinated people who do get sick, breakthrough infections provide a boost in immunity, according to research from December. “People who have had both the illness and vaccination have much higher levels of antibodies than those people who just have recovered and have not been vaccinated,” says William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center. “And higher levels of antibody are associated with a longer duration of protection.” If you’ve recently recovered from Covid-19 and are unvaccinated, Schaffner advises getting the shot to capitalize on this protective combination.
Is it safe to go to restaurants and bars after a Covid-19 infection?
You’re extremely unlikely to be reinfected with the same variant within a month or two of recovering from Covid-19, Bailey says. One scientific review of published research on Covid-19 immunity suggested that antibody levels begin to decline three months after a previous infection. However, when you gain immunity to one variant, you don’t necessarily gain immunity to others: It is possible to be swiftly reinfected with omicron after you recover from delta. So a breakthrough infection isn’t permission to live it up like it’s 2019.
Because there will always be a risk of reinfection, Bailey suggests thinking about immunity in the weeks following recovery as a little like airbags in a car. Airbags protect drivers from serious injury, but risky behaviors like texting, speeding, or careless driving offset the benefits of the airbag. Something similar is true of post-infection immunity: Antibodies provide protection, but persistent high-risk activities — like going unmasked in a crowded bar — increase risk of reinfection.
That’s not to say recently recovered people don’t have any wiggle room. They just have to decide how much risk they’re willing to tolerate. In the initial months post-infection, most healthy vaccinated people who are not immunocompromised have a low risk of severe reinfection, Bailey says, meaning they can move about the world knowing a visit to the gym won’t kill them.
“They do have a level of risk that’s similar to other things that we tolerate,” like driving on the highway, Bailey says. “Therefore, doing things like going out to a restaurant, potentially traveling, becomes something that is safer, and is safer still if you wear masks as much as you can and you’re not going to really super high-density things like a rave or a mosh pit. Those things will still push your risk back up again.”
What other fun stuff can I do safely now, and what precautions are necessary?
If you’re thinking of getting on a plane or attending an indoor sporting event, Bailey says to ensure you’re still taking precautions, like masking and avoiding crowds as best you can. “Even though I have my airbag, I’m still going to put my seatbelt on, I’m still going to pay attention to the traffic,” he says. “As I take that extra level of risk, I’m thinking about what else I can do in my immediate environment that limits unnecessary elevation of risk.”
Schaffner agrees that recently recovered folks should still be wary of crowds and should continue to mask up indoors. “It’s not recommended that they be carefree and say, ‘Okay, I’ve gotten a get out of jail free card, I can do whatever I want,’” he says. Should you decide on a post-illness vacation, ensure you’re still testing and masking, especially if you are visiting with an elderly grandparent or immunocompromised friend during or after your trip, Schaffner advises.
While Schaffner says it’s unlikely in the short term that you’ll get an infection and spread it, it’s still possible. The more time that passes following your recovery, the more likely it is that you could get reinfected and spread the virus. The CDC continues to recommend that anyone who tests positive go into isolation, even if they’re asymptomatic.
The risk of future variants should make people a little more careful about post-infection behavior, Schaffner says. When a new variant emerges, the world may face another round of wait-and-see uncertainty to determine how well vaccination, protection from prior infection, and hybrid immunity hold up against the mutated virus.
Ultimately, what activities you decide to partake in after recovering from Covid-19, Schaffner says, comes down to how much risk you’re willing to withstand. “If you’re 72 years old with diabetes, everything is at risk. That’s what I would tell all my patients,” he says. “If you’re 28 years old and otherwise completely healthy and you’ve recovered, the first thing I would ask you is, ‘Are you vaccinated?’ Those folks can go out.” But because nothing is “safe” or comes without risk, he recommends everyone masks in indoor environments.
As cases subside, the overall risk will, too: Less virus in the community means less chance of catching it and spreading it. On top of that, you can probably breathe a tentative sigh of relief for a few weeks post-infection, as long as you continue to avoid unnecessary risks, like crowded dance floors, and mask up around vulnerable loved ones and anyone outside your household.