What Is the B.1.1.7 Variant?

What to know about this COVID-19 mutation, also known as the Alpha variant

All viruses develop mutations and variants, and COVID-19 is no different. Since the start of the COVID-19 pandemic, multiple variants of the virus have developed. One of these variants is B.1.1.7, which was initially found in the United Kingdom in September 2020.

Also known as the Alpha variant, B.1.1.7 was once the dominant strain in the United States.

COVID-19 B.1.1.7. variant

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Where B.1.1.7 Has Spread

The B.1.1.7 variant has now spread to at least 164 countries worldwide, including the United States. Initially, the virus was spread to other countries by infected travelers from the United Kingdom. Despite this spread, the Delta variant (B.1.617.2) has now become the dominant strain in most European countries.

Spread in the United States

The B.1.1.7 variant was initially found in the United States in December 2020, with the first case found in Colorado.

As of July 17, 2021, the ten states with the highest percentage of the B.1.1.7 variant among COVID-19 cases were:

  • Louisiana
  • Tennessee
  • Minnesota
  • Washington
  • Virginia
  • South Carolina
  • Georgia
  • North Carolina
  • Texas
  • Alabama

The variant has now been found in every state, and although it was once the dominant cause of new COVID-19 infections in the United States, the Delta variant now accounts for over 90% of new cases.

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 B.1.1.7 More Contagious?

The B.1.1.7 variant has been found to be at least 50% more contagious than the original COVID-19 virus.

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; 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 B.1.1.7 variant.  

Globally, the R0 for COVID-19 varies, but with the B.1.1.7 variant, the R0 is increased at least 50%, leading to an exponential increase in transmission. 

Preventing Transmission

Precautions to prevent the transmission of the B.1.1.7 variant are the same as for the original COVID-19 virus and should continue to be followed. Precautions if you're unvaccinated include:

• Stay 6 feet apart from others who don’t live in your house

• Wear a mask that covers your mouth and nose

• Wash your hands often or use 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 go without a mask and physical distancing in places where it isn't required by federal, state, or local regulations. Good hand hygiene is still recommended.

Risk of Reinfection

A study done in the United Kingdom did not demonstrate increased rates of COVID-19 reinfection related to the B.1.1.7 variant.

Is B.1.1.7 More Severe?

Initially, it was thought that the B.1.1.7 variant may cause an increased risk of death.

However, in a study published in April 2021, it was found that the B.1.1.7 variant was not found to be associated with an increased risk of symptoms, severe disease, or death.

The CDC does still state, though, that there is possibly an increased severity based on hospitalizations and case fatality rates.

Will Vaccines Work Against B.1.1.7?

The World Health Organization (WHO) has reported that vaccines from Pfizer/BioNTech and Moderna continue to be highly effective against the B.1.1.7 variant. Vaccines produced in other countries appear to be effective against this variant as well.

Results of one study show the Pfizer/BioNTech vaccine to be 93% effective against the Alpha variant. Another study (which has yet to be peer-reviewed) shows the Moderna vaccine is also capable of providing protection.

There is currently little data on the effectiveness of the Johnson & Johnson vaccine against this variant, though according to information released by the company, the vaccine generates neutralizing antibodies against a range of COVID-19 variants, including B.1.1.7.

Are Kids More at Risk for B.1.1.7?

Studies from the United Kingdom have shown increased numbers of children and young adults being infected with the B.1.1.7 variant. However, this does not mean that children are more at risk for infection of the B.1.1.7 variant.

Studies have found children who become infected have mild symptoms or no symptoms at all, and there is no evidence of increased risk of severe disease or hospitalization in children.

A Word From Verywell

Experts are concerned about the spread of the B.1.1.7 variant of COVID-19 around the world and in the United States. As this variant is more contagious, it has the opportunity to spread quickly.

Continuing to follow precautions as recommended by the CDC and getting a vaccine when it is available to you 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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15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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