Not again: sore throat, cough, and chills. You may feel like you just got it when a positive COVID-19 test comes back.

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?

The risk of reinfection is increasing. We discuss what we know about the reinfections in this article.

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

  • The emergence of new coronaviruses.
  • Natural immunity is waning from vaccinations.
  • There was a decrease in COVID-related precautions.

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.

The landscape of reinfections has changed because of Omicron and its subvariants. Here is what the research has found.

Pre-Omicron reinfections

Before Omicron, re-infections were not that common. Research shows that protection from reinfection can last for 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.

Unvaccinated people have waning immunity from a prior infection. Even if a prior infection was over 18 months ago, immunity stayed high in people who had COVID-19.

Summary

COVID-19 could protect against reinfection for several months. This level of protection was boosted by the vaccine.

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.

Summary

Omicron is less protected against previous infections and vaccinations. If you had COVID-19 before Omicron, you are less protected against reinfection now than you were before.

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.

The neutralizing subvariants of the anti-vaccines were harder to find. The original Omicron variant that was dominant in late 2021 and early 2022, was the reason for the lower neutralization.

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.

If you had COVID-19 during the first or most recent wave, you can re-infection with BA.4 or BA.5 now. It is likely that you are 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.

Summary

BA.4 and BA.5 are very good at escaping the effects of vaccinations. This includes previous Omicron infections.

If you had COVID-19 in the past, you are at risk of getting it again now. This is likely why there are so many anecdotal reports of people getting COVID-19.

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:

The effects were seen regardless of vaccination status. The number of infections reported in the study increased the level of risk.

The study may not reflect risk in the general population. People use Veterans Affairs healthcare resources. The study population is more likely to be older and male.

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:

  • It can happen in anyone.
  • It happens 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
  • They often resolve on their own after a few days without additional 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.

People who had third infections had their first and second infections early in the Pandemic and Delta variant wave. Omicron was their third infection.

What’s the best way to prevent reinfections?

The best way to prevent getting COVID-19 reinfections is to take steps to protect yourself.

  • staying up to date on your COVID-19 vaccines
  • When you are out in public, wear a mask that is well-fitting.
  • washing your hands frequently
  • Avoid crowded areas or poorly ventilated spaces.
  • Trying to stay away from other people outside of your house.

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 re-infections is increasing. You may hear more and more about people getting COVID-19 for a second time, sometimes not too long after their first infections, because of this.

The Omicron BA.4 and BA.5 subvariants are the main cause of the latest re infections. Reduced COVID-19 precautions and waning immunity are some of the things that contribute.

First infections of COVID-19 are usually less severe than the re-infections. Some research says that repeat infections increase the risk of health issues. It is important to continue to take steps to prevent COVID-19.