Researchers are still studying how quickly you can be reinfected with COVID-19. Factors that may contribute to reinfection include waning immunity and emerging new variants.

Cough, sore throat, fever, and chills: Not again! When a positive COVID-19 test comes back, you may feel like you just had it.

As time passes, immunity wanes, and new virus variants emerge. So, reinfections are certainly possible. But can you get COVID-19 twice in just 1 month?

While that specific scenario is pretty unlikely, the risk of reinfection is increasing. In this article, we discuss what we know so far about COVID-19 reinfections.

Generally, a number of factors contribute to COVID-19 reinfections. These include the:

  • emergence of new coronavirus variants
  • natural waning immunity gained from vaccination or previous infections
  • decrease in COVID-related precautions like mask wearing and physical distancing

According to the Centers for Disease Control and Prevention (CDC), we’re still learning many things about COVID-19 reinfections. This includes how soon reinfection can happen.

Before the arrival of the Omicron variant, reinfections weren’t that common. Researchers in a May 2022 study looked at reinfections from the start of the pandemic until Omicron. Overall, they found that reinfection risk was 6.7% in the 18 to 22 months after a first infection.

However, now Omicron and its subvariants have changed the landscape of reinfections. Here’s what the research has found.

Pre-Omicron reinfections

Reinfections weren’t that common before Omicron. Research found that protection from reinfection typically lasted for at least several months.

A 2021 study looking at PCR testing data from 2020 found that a prior infection still gave about 80% protection 6 months after a first infection.

A February 2022 study brought vaccination into the mix. Researchers looked at the effect of vaccination on reinfection from December 2020 to September 2021.

Immunity from a prior infection waned after 1 year in unvaccinated people. However, in people vaccinated after having COVID-19, immunity stayed high, even if a prior infection was over 18 months ago.


Before Omicron, having had COVID-19 could protect against reinfection for at least several months. Vaccination boosted this level of protection.

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Post-Omicron reinfections

Viruses can change over time, and that’s certainly been true with this coronavirus. As changes accumulate, they can make it easier for a virus to escape immunity generated by vaccination, a previous infection, or both.

A July 2022 study, still in preprint, looked into the qualities of protection that a pre-Omicron infection provided:

  • Reinfection with another pre-Omicron virus: The effectiveness of a pre-Omicron infection against another pre-Omicron infection was 85.5%. Researchers estimated this would reach less than 10% by 32 months.
  • Reinfection with Omicron: The effectiveness of a pre-Omicron infection against an Omicron infection was significantly lower at 38.1%. Researchers estimated this would reach less than 10% by 15 months.

A June 2022 study looked at the protection previous infection and vaccination provided on symptomatic infections with the “original” Omicron variant (BA.1) or its first subvariant, BA.2. Overall, there was no difference in protection between people who were vaccinated, who had had a previous infection, or both.


Previous infection and vaccination provide less protection against Omicron. This means that if you had COVID-19 before Omicron, you’re less protected against reinfection now than you were before Omicron.

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Omicron BA.4 and BA.5

The new BA.4 and BA.5 Omicron subvariants are now the main drivers of COVID-19 in the United States. They’re also very good at escaping the immune system.

A July 2022 study looked into the neutralization of BA.4 and BA.5 by antibodies from vaccination or a previous COVID-19 infection. Neutralizing antibodies prevent the virus from binding to a host cell.

Antibodies from vaccinated people had a harder time neutralizing these subvariants. Neutralization was also lower with antibodies from people with a prior infection, including BA.1, the “original” Omicron variant that was dominant in late 2021 and early 2022.

Another July 2022 study supports this. Researchers found that neutralization of BA.4 and BA.5 was lower than that of BA.1 or BA.2 in both vaccinated people and those with a prior infection.

What this means is that if you had COVID-19 during the first or most recent (BA.2) Omicron wave, reinfection with BA.4 or BA.5 is possible now. However, it’s still pretty likely you’re well protected at this point in time.

Researchers in a July 2022 study, still in preprint, found that while the effectiveness of a pre-Omicron infection against symptomatic BA.4 or BA.5 infections was only 15.1%, it was still rather high (76.1%) if you had a previous Omicron infection.


BA.4 and BA.5 are very good at escaping antibodies from vaccinations and previous infections. This includes previous Omicron infections.

What this means is that if you had COVID-19 in the past, you’re potentially at risk of getting it again now. This is also likely why there are so many anecdotal reports of people getting COVID-19 two times in a row.

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COVID-19 reinfections appear to be less severe than first infections. A 2021 study looked at the risk of serious illness or death from reinfections. Compared with first infections, reinfections had a 90% lower risk of serious illness or death.

An April 2022 study also found that COVID-19 reinfections carried a lower risk of death than first infections. Similar to first infections, age, sex, and underlying health conditions were risk factors for severe illness from reinfection.

However, there’s some evidence that reinfections may increase the risk of lasting health effects. A June 2022 study, still in preprint, found that, compared with first infections, reinfections boosted the risk of:

  • problems with:
    • the lungs, cardiovascular system, and many other organ systems
  • hospitalization
  • death from any cause

These effects were seen regardless of vaccination status. The level of risk was also found to increase in line with the number of infections study participants reported.

One limitation of this study is that it may not reflect risk in the general population. Researchers focused on people using Veterans Affairs (VA) healthcare resources. As such, the study population is more likely to be older and male, and have poorer health.

Paxlovid is an antiviral drug doctors prescribe to treat mild to moderate COVID-19 in people at high risk of severe illness. To be effective, Paxlovid needs to be started within 5 days of symptom onset.

Rebounds of COVID-19 have been reported after Paxlovid treatment. While it’s still unclear why this happens, it’s possible that the coronavirus isn’t completely cleared from the body while taking Paxlovid, allowing it to replicate again after treatment ends.

Increasing reports of these rebounds prompted the CDC to release a health advisory. In this advisory, the CDC noted that Paxlovid rebounds:

  • can occur in anyone, regardless of vaccination status
  • typically happen between 2 and 8 days after Paxlovid treatment
  • are characterized by a new positive COVID-19 test after previously testing negative, which can also include a return of mild symptoms
  • often resolve on their own after a median of 3 days without additional antiviral treatment

Rebounds after Paxlovid are rare. A June 2022 study found that, of 483 people treated with Paxlovid, only 4 (0.8%) had a rebound. Another June 2022 study, still in preprint, found a higher rebound rate: about 3.5% in the 7 days after treatment.

People experiencing COVID-19 rebound after Paxlovid may also be able to transmit the infection to others. A small May 2022 study, still in preprint, involving 10 people documented transmission to family members during rebounds.

The amount of virus during a rebound was also similar to where it was before Paxlovid treatment. Researchers stated that these findings support that people who are having a rebound should isolate until their symptoms go away.

COVID-19 rebounds may also happen without taking Paxlovid. A June 2022 research article mentions anecdotal reports of rebounds in people who never took Paxlovid. Authors note that perhaps Omicron takes longer to clear in some people than earlier virus variants.

Can you get COVID-19 a third time in a row?

Yes. A study published in March 2022 signaled an increased risk of reinfections due to Omicron. Within the study population, researchers noted that an increase in third infections was seen beginning in November 2021.

Researchers stated that people who had third infections had their first infection early in the pandemic and a second infection during the Delta variant wave. Their third infection was from Omicron.

What’s the best way to prevent reinfections?

The best way to prevent getting COVID-19 reinfections is to continue to take steps to protect yourself, including:

  • staying up to date on your COVID-19 vaccines
  • wearing a well-fitting mask when you’re out in public, especially in indoor places
  • washing your hands frequently
  • avoiding crowded areas or poorly ventilated spaces
  • trying to stay a distance of 6 feet apart from others outside your household

How long should you quarantine after a COVID-19 reinfection?

According to the CDC, we know little about the risk of transmission during COVID-19 reinfections. Overall, it’s best to err on the side of caution and assume you can transmit the virus to others.

A July 2022 study found that viral shedding (aka the contagious period) among people with Omicron infections can last up to 10 days.

So, it’s a good idea to isolate and quarantine for at least 10 days or until you are symptom-free and test negative from a rapid COVID-19 test.

How soon will the boosters that target Omicron variants be available?

According to the Food and Drug Administration (FDA), boosters targeting Omicron are slated to be available starting in fall 2022. The FDA has also recommended a BA.4 and BA.5 component be included in this booster.

Moderna has announced that its Omicron booster yields a significantly higher neutralizing antibody response to BA.4 and BA.5 than its current booster.

Pfizer-BioNTech stated that, compared with their current booster, their Omicron booster gave higher levels of neutralizing antibodies against BA.1. Neutralizing antibodies for BA.4 and BA.5 were present but to a lesser extent.

The risk of COVID-19 reinfections is increasing. Because of this, you may hear of more and more people in your life getting COVID-19 for a second time, sometimes not too long after their first infection.

The latest reinfections are largely driven by the Omicron BA.4 and BA.5 subvariants, which can escape immunity from vaccines and prior infections. Things like naturally waning immunity and reduced COVID-19 precautions also contribute.

Reinfections of COVID-19 are typically less severe than first infections. However, some research says that repeat infections increase the risk of health issues later. As such, it’s important to continue to take steps to prevent COVID-19.