What Is the P.1 Variant?

What to know about this COVID-19 mutation

Since the start of the COVID-19 pandemic, multiple variants of the virus have developed. One of these variants is P.1, which was discovered in four travelers from Brazil as they were screened at an airport in Japan in January 2021.

COVID-19 variant

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Where P.1 Has Spread

The P.1 variant has now spread to at least 52 countries worldwide, including the United States. It is the dominant strain of COVID-19 in Brazil.

Spread in the United States

The P.1 variant was initially found in the United States in January 2021 in Minnesota.

The P.1 variant is responsible for 1.4% of new COVID-19 cases in the United States. There have been less than 500 total confirmed cases of the P.1 variant in the United States, and it has been found in 31 states.

Why Do Viruses Mutate?

It is common for all viruses to mutate. When a virus enters the body, it begins to make copies of itself.

Sometimes during this process, mistakes (mutations) are made in the copies, which can make it easier for the virus to invade the cell. When this same mutation continues to further copy itself, a variant of the virus forms.

Is P.1 More Contagious?

The P.1 variant is thought to be more contagious than the original COVID-19 virus based on data from Brazil, but details on the increased risk of transmission have not been reported.

The infectiousness of a virus is measured by a reproduction number—called R0—which measures the number of people an infected person will give the virus to. For example, if the R0 is 1, an infected person is likely to give it to one other person, and an R0 of 5 means an infected person is going to transmit it to five other people. We do not yet know the R0 for the P.1 variant.  

Preventing Transmission

Precautions to prevent the transmission of the P.1 variant are the same as for the original COVID-19 virus and should continue to be followed. These precautions include:

  • Staying 6 feet apart from others who don’t live in your household
  • Wearing a mask that covers your mouth and nose
  • Practicing good hand hygiene by washing hands often or using hand sanitizer 

If you are fully vaccinated, the Centers for Disease Control and Prevention (CDC) has released new guidelines that say it is safe to gather indoors with other fully vaccinated people and to not wear a mask when outdoors, unless it is a crowded setting or venue.

Risk of Reinfection

It is possible that the P.1 variant can cause reinfection.

Data from Brazil confirmed that it’s possible to be infected with the original strain of COVID-19 and then become reinfected with the P.1 variant. However, further studies are needed to continue to investigate and help determine the risk of reinfection.

Is P.1 More Severe?

Data on the severity of COVID-19 infection from the P.1 variant is limited. However, what is currently available in a study from Brazil does not suggest an increase in disease severity from the P.1 strain.

Recent studies did uncover that specific monoclonal antibody treatments may be less effective for treating cases of COVID-19 caused by the P.1 variant.

Will Vaccines Work Against P.1?

The World Health Organization (WHO) has reported that the P.1 variant may cause a mild decrease in the effectiveness of vaccines, while some vaccines not in use in the United States are showing effectiveness against this strain. Studies are still ongoing, with more data to come.

Are Kids More at Risk for P.1?

Currently, there is little data available about the risk of P.1 in children. However, there is no current evidence suggesting this virus causes an increased risk of infection or more severe disease in children.

A Word From Verywell

Experts are worried about the spread of the P.1 variant of COVID-19 around the world and in the United States.

Following precautions as outlined by the CDC and getting a vaccine when it is available to you, as long as it safe for you to do so, is important to help decrease the spread of this and other variants of COVID-19.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

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Article Sources
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  1. Centers for Disease Control and Prevention. Science brief: emerging SARS-CoV-2 variants. Updated January 28, 2021.

  2. World Health Organization. Weekly epidemiological update on COVID-19 - 13 April 2021.

  3. Centers for Disease Control and Prevention. First identified cases of SARS-CoV-2 variant P.1 in the United States - Minnesota, January 2021. Updated March 2021.

  4. Centers for Disease Control and Prevention. COVID-19 tracker. Updated April 19, 2021.

  5. Cleveland Clinic. What does it mean that the coronavirus is mutating? Updated January 11, 2021.

  6. Centers for Disease Control and Prevention. How to protect yourself & others. Updated March 8, 2021.

  7. Centers for Disease Control and Prevention. When you’ve been fully vaccinated. Updated April 27, 2021.

  8. Sabino EC, Buss LF, Carvalho MPS, et al. Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalenceThe Lancet. 2021;397(10273):452-455. doi:10.1016/S0140-6736(21)00183-5

  9. Faria NR, Mellan TA, Whittaker C, et al. Genomics and epidemiology of a novel SARS-CoV-2 lineage in Manaus, BrazilmedRxiv. Published online March 3, 2021:2021.02.26.21252554. doi:10.1101/2021.02.26.21252554

  10. Centers for Disease Control and Prevention. SARS-COV-2 variant classifications and definitions. Updated April 27, 2021.