Frequently asked questions about the coronavirus: I have COVID. Then I have it again. What is reinfection all about?


A positive result on a home COVID test. If you catch it once, can you catch it again? Turns out the answer is: Yes. (Jakub Porzycki/NurPhoto via Getty Images)

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You got sick with COVID in January so you thought you were done with the virus for a while. But then you began to feel a sore throat and a runny nose, did a home test just in case — and this second line flared up red again.

You may be wondering: how can this happen? Is it possible to catch COVID again just months or even weeks after recovering from a case?

We asked four specialists to answer frequently asked questions about reinfection.

I thought I was immune – at least for a while – after having COVID. Is not that the case?

If you caught an earlier variant – before the arrival of omicron – it meant you had an 84% reduced risk of infection, significantly lowering your risk of contracting COVID again, especially in the months immediately following your illness .

But the omicron variants have changed that.

A study published in March found that the risk of reinfection “substantially increased” 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 Omicron variants now circulating around the world and they are very transmissible and very good at overcoming immunity, whether through vaccination, previous infection or both.

Not only do these Omicron variants bypass the protection you may have received from a non-Omicron version of SARS-CoV-2; You can catch the newer variants of omicron even if you previously had the original omicron variant.

And any protection against infection wears off over time. So if it’s been a few months since your last COVID shot or you’ve recovered from a case, you’re more likely to get infected again.

But there’s some good news: for now, the latest Omicron variants don’t seem to be doing any better at overcoming immunity than the original Omicron.

The recent resurgence in South Africa is now being driven by the omicron sub-lineages BA.4 and BA.5. With these variants, “the risk of reinfection appears to be about the same as with BA.1—that is, higher than the previous ones [non-omicron] Variants but no higher than the original circulating Omicron subline,” Pulliam told NPR in an email.

How soon could I get infected again?

Experts are still trying to find out. But 60% of reinfections of non-omicron variants between March 2020 and March 2021 in Denmark occurred less than two months after initial infection, researchers found in a preprint study that was not peer-reviewed or published.

This means you may have a shorter period of maximum protection after infection than you thought.

As a reminder, the Danish researchers only examined 15 confirmed reinfections among 593 suspected cases. The number is low for several reasons: Firstly, reinfections were not that common back then.

Because the newer variants are much better at overcoming previous immunity, our specialists say if you’ve recently recovered from a case of COVID and then show COVID-like symptoms, you should get tested to see if you can get it again to have.

Is reinfection mild or could it be serious?

Research from South Africa suggests that previous infection protects against serious consequences, including hospitalization and death.

Hospitalizations and deaths from reinfection seem uncommon, but both natural infections and vaccinations seem to provide good protection from severe outcomes in most people, Pulliam says.

Another study from Qatar found that prior infection protected about 87% from severe or fatal COVID-19.

However, keep in mind that certain medical conditions – such as such as an organ transplant, ongoing cancer treatments, or heart or lung disease — making you more vulnerable to adverse outcomes, even if you previously encountered the virus through vaccination or infection.

“In immunocompromised patients,” the intensity of the disease “depends on the patient and how compromised their immune system is,” says Jacob Lemieux, an infectious disease physician at Massachusetts General Hospital. “We can’t say exactly what the effect would be.”

However, the intensity of your illness also depends on how long it has been since your last vaccination or previous COVID bout, as such protection wears off over time – so it’s a good idea to keep your vaccination schedule up to date.

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 University of California, San Francisco School of Medicine, when some patients develop symptoms and test positive again, this is probably not an example of reinfection, but something else known as a “rebound.” 2 to 8 days after taking the drug.

That happened to Wachter’s wife. After taking Paxlovid, her symptoms improved significantly 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 headache, and when they came back it felt like a really bad cold with constipation – and she tested positive again.

The potential for a rebound caused him to reconsider using Paxlovid in younger people who aren’t as at risk of serious consequences, he says. But if he did get sick, he would still take Paxlovid because of his own potential risk factors.

That’s because Paxlovid reduced the rate of hospitalizations in high-risk individuals by 89% in clinical trials, allowing those who have risk factors, such as This protection applies to both vaccinated and unvaccinated people who are at high risk, according to a new study.

“That’s right,” says Wachter. “How sensible that makes sense for you really depends entirely on your hospitalization rate and how much risk you have of a bad case that would make you very ill and potentially hospitalize you or possibly kill you.”

Do vaccinations help prevent reinfection?

Getting vaccinated can help prevent infection and reinfection, so it’s a good idea to get vaccinated even if you’ve had COVID before and thought you were protected.

“The vaccinated and infected are much better protected,” says Peter Palese, professor and chair of the Department of Microbiology at the Icahn School of Medicine at Mount Sinai.

Especially if you previously had a severe case, updating your COVID shots now means you’re likely to have a less severe case if you get infected again, Palese says.

“Vaccination vaccination. Because yes, it doesn’t protect you from getting a mild illness, but it does protect you from being on a ventilator, being in intensive care,” or dying, he says.

But the immunity that vaccinations offer, especially against infection, starts to wane after a few months, so getting a booster (or a second booster if you’re eligible) is a very good idea.

If you were previously hospitalized with COVID and then received two mRNA vaccines, this protective blend was 35% effective in preventing subsequent hospitalizations during the first Omicron wave. If you received a booster shot, that number rose to 68%, which is effective against hospitalization.

And no vaccine is perfect, so precautionary measures — wearing a mask, getting tested if you have symptoms or are exposed to COVID, improving ventilation, and more — are still recommended, especially during surges like the one we’re experiencing the US is currently experiencing.

Can multiple COVID illnesses have long-term effects?

Long-term damage from repeated reinfections, like organ damage, is “the big question, and I haven’t seen any data that can address that,” Pulliam says.

And experts believe any COVID case could result in a long COVID, even if you were fine the last time.

According to a study published by the US Centers for Disease Control and Prevention, after acute COVID cases, one in five adults experience ongoing health problems, including “persistent symptoms or organ dysfunction.”

“There seems to be a risk of long COVID or symptoms after the acute infection has cleared in a subset of people, and we don’t really know yet how common that is or how long it lasts,” says Lemieux.

How should I deal with the emerging – and changing – information about reinfection risks?

“It’s a really frustrating situation because I think everyone wants to deal with this virus but we just aren’t. And we live in a time when we just want complete information at our fingertips, but we don’t have it. ‘ says Lemieux.

This means we must remain vigilant as each new variant changes and how we respond to it—especially in the age of reinfection.

The same precautions used to prevent infection — masks, distancing, vaccinations, and more — work just as well to avoid reinfection.

Another point to note is that coronavirus reinfections are not that uncommon. “I don’t think it’s surprising that reinfection is happening because that’s a feature of coronavirus biology,” says Lemieux. “Actually, it’s rather surprising that this didn’t happen more often with the first variants.”

Melody Schreiber (@m_scribe) is a journalist and editor of What we didn’t expect: Personal stories about preterm birth.

Copyright NPR 2022.

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