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We regularly answer frequently asked questions about life during the coronavirus crisis. If you have a question that you would like us to consider in a future post, please email us at [email protected] with the subject line: “Weekly questions about the coronavirus”. View an archive of our FAQs here.
You got sick with COVID in January, so you figured you were done with the virus for a while. But then you started feeling a scratchy throat and a runny nose, took a home test just in case – and that second line glowed red once more.
You must be wondering: how can this happen? Is it possible to get COVID again just a few months or even weeks after recovering from a case?
We asked four experts to answer frequently asked questions about reinfection.
I thought I was immune – at least for a while – after having COVID. That’s not the case?
If you caught an earlier variant – before the arrival of omicron – that meant you had an 84% lower risk of infection, significantly reducing your risk of getting COVID again, especially in the months right after you got sick.
But the omicron variants changed that.
A study published in March found that the risk of reinfection “increased substantially” with the emergence of omicron in November, says Juliet Pulliam, lead author of the study and director of the South African Center for Epidemiological Modeling and Analysis.
There are several variants of omicrons circulating around the world, and they are very transmissible and very good at overcoming immunity, whether through vaccination, prior infection, or both.
These omicron variants not only evade the protection you might have gotten from a non-micron version of SARS-CoV-2; you can get the latest omicron variants even if you already had the original omicron variant before.
And any protection from infection diminishes over time, so if it’s been a few months since your last COVID injection or since you’ve recovered from a case, you’re more likely to be susceptible to reinfection.
But there’s some good news: for now, the newer omicron variants don’t seem any better at overcoming immunity than the original omicron.
The most recent resurgence in South Africa is now being driven by the omicron sublineages BA.4 and BA.5. With these variants, “the risk of reinfection appears to be about the same as it was for BA.1 – so much higher than for [non-omicron] variants, but not superior to the initially circulating omicron sublineage,” Pulliam told NPR in an email.
How soon could I be reinfected?
This is something that experts are still trying to figure out. But 60% of reinfections of non-micron variants between March 2020 and March 2021 in Denmark occurred less than two months after the first infection, researchers found in a preprint study, which has not been peer-reviewed or published.
This means you may have a shorter maximum protection time than you thought after an infection.
Remember: Danish researchers looked at just 15 confirmed reinfections among 593 suspected cases. The number is low for a few reasons: on the one hand, reinfections were not so common at the time.
Because the newer variants are much better at overcoming previous immunity, our experts say that if you’ve recently recovered from a COVID case and started showing COVID-like symptoms, you should get tested to see if you have it again.
Is a reinfection more likely to be mild or could it be severe?
Research from South Africa suggests that prior infection protects against serious outcomes, including hospitalization and death.
With reinfection, hospitalization and death “seems to happen occasionally, but both natural infection and vaccination seem to provide good protection against serious outcomes in most individuals,” Pulliam says.
Another study from Qatar found that previous infection was about 87% protective against severe or fatal COVID-19.
But keep in mind that certain conditions — such as having an organ transplant, ongoing cancer treatments, or heart or lung disease — make you more vulnerable to poor outcomes, even if you’ve found the virus earlier through vaccination or infection.
“In immunocompromised patients,” the severity of the disease “depends on the patient and depends on how weakened their immune system is,” says Jacob Lemieux, an infectious disease physician at Massachusetts General Hospital. “We cannot say precisely what the effect would be.”
But the intensity of your illness also depends on how much time has passed since your last vaccination or previous COVID attack, as this protection diminishes over time – so keeping up to date on your vaccination schedule is a good idea.
I took Paxlovid and a few days later I tested positive again. Is this a reinfection?
According to Robert Wachter, professor and chair of the department of medicine at the University of California, San Francisco, this is likely not an example of reinfection, but something different, known as “rebound,” when some patients begin to experience symptoms and test positive again. 2 to 8 days after taking the medicine.
That’s what happened to Wachter’s wife. After taking Paxlovid, her symptoms markedly improved and she began to test negative on rapid tests. But four days later, she developed new symptoms — in the first round, she had a sore throat, fatigue, and a headache, and when she came back, it felt like a very bad cold with congestion — and she tested positive again.
The potential for recovery has made him rethink using Paxlovid among younger people who aren’t as at risk of serious outcomes, he says. But if he got sick, because of his own potential risk factors, he would still take Paxlovid.
That’s because in clinical trials, Paxlovid has lowered the hospitalization rate by 89% among high-risk people, so those who have factors that put them at risk, such as being immunosuppressed or being over 65, see a big benefit in taking the antiviral. . That protection holds true for both vaccinated and unvaccinated people who are at high risk, according to a new study.
“This is real,” says Wachter. “How significant this is for you really depends entirely on your hospitalization rate and the risk you have of a serious case that would make you very sick and potentially put you in the hospital or potentially kill you.”
Do vaccines help prevent reinfection?
Vaccination can help prevent infections and reinfections, so it’s a good idea to get the vaccines even if you’ve had COVID before and thought you were protected.
“For those who are vaccinated and those who have been infected, they are much better protected,” says Peter Palese, professor and chair of the microbiology department at the Icahn School of Medicine at Mount Sinai.
Especially if you’ve had a severe case before, updating your COVID vaccines now means you’re likely to have a less severe case if you’re reinfected, says Palese.
“Vaccination vaccination vaccination. Because yes, it will not protect you against the onset of mild disease, but it will protect you from having a ventilator, being in the ICU” or dying, he says.
But the immunity offered by vaccines, especially against infection, starts to wane after a few months, so getting a booster (or a second booster, if you’re eligible) is a good idea.
If you were hospitalized before with COVID and then received two mRNA vaccines, this combination of protection was 35% effective in preventing subsequent hospitalizations during the first omicron wave. If you got a booster, that number went up to 68% effective against hospitalization.
And no vaccine is perfect, so continuing to take precautions — wearing a mask, getting tested if you have symptoms or are exposed to COVID, improving ventilation, and more — is still recommended, especially during outbreaks like what the US is seeing. currently.
Can getting COVID multiple times have long-term effects?
Long-term harm from repeated reinfections, such as organ damage, is “the big question, and I haven’t seen any data that can address it,” Pulliam says.
And experts believe that every COVID case can lead to a long COVID, even if you were fine the last time.
One in five adults has ongoing health problems after acute cases of COVID, including “persistent symptoms or organ dysfunction,” according to a study published by the US Centers for Disease Control and Prevention.
“There appears to be a risk of COVID or long-term symptoms after the acute infection has resolved in a subset of people, and we still don’t know how common this is or how long it lasts,” says Lemieux.
How should I deal with emerging – and changing – information about reinfection risks?
“It’s a really frustrating situation because I think everybody wants to end this virus, but we just don’t. And we live in an era where we just want complete information at our fingertips, but we don’t have it.” Lemieux says.
That means we need to be mindful of the ways each new variant is changing and how we respond to it – especially in the age of reinfection.
The same precautions used to prevent infection — masks, distancing, vaccines, and more — work just as well to prevent reinfection.
Another point to keep in mind is that reinfections are not that uncommon for coronaviruses. “I don’t find it surprising that reinfection happens, because that’s a feature of the biology of the coronavirus,” says Lemieux. “It’s really surprising, if anything, that this hasn’t happened more often with early variants.”
Melody Schreiber (@m_scribe) is a journalist and editor at What we didn’t expect: personal stories about preterm birth.