Where B.1.427 and B.1.429 Have Spread

The B.1.427 and B.1.429 variants, also known as the Epsilon variants, have now spread from the United States to at least five countries worldwide.

Spread in the United States

The B.1.427 and B.1.429 variants were initially found in California in February 2021, but are no longer the dominant strains in the state.

As of June 8, 2021, the B.1.427 and B1.429 variants were responsible for about .5% of new cases in the U.S. overall and were expected to continue declining. Although, they still accounted for 5% of cases in California and more than 9% of cases in Washington and Oregon.

They have been found in at least 28 states.

Are Epsilon Variants More Contagious?

The B.1.427 and B.1.429 variants are thought to be more contagious than the original COVID-19 virus based on data from the United States. Some studies have suggested a 20% increased transmission rate with the B.1.427 and B.1.429 variants.

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.

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.1.427 and B.1.429 variants.

Risk of Reinfection

There aren’t any currently reported data regarding the risk of reinfection of COVID-19 due to the Epsilon variants.

Stay 6 feet apart from others who don’t live in your householdWear a mask that covers your mouth and nosePractice good hand hygiene by washing hands often or using hand sanitizer

If you are fully vaccinated, the CDC has released new guidelines that say you can go without a mask and physical distancing in places where it isn’t required by federal, state, or local regulations.

Regular hand washing is still recommended.

Is Epsilon More Severe?

Data on the severity of COVID-19 infection from the B.1.427 and B.1.429 variants is limited. At this time, there is no evidence to suggest that the B.1.427 and B.1.429 variants cause more severe disease.

Recent studies did uncover that specific monoclonal antibody treatments may be less effective for treating cases of COVID-19 caused by the B.1.427 and B.1.429 variants.

Will Vaccines Work Against Epsilon?

The World Health Organization (WHO) has reported that the B.1.427 and B.1.429 variants may cause a mild decrease in the effectiveness of vaccines. Studies are still ongoing, and more information will continue to be released.

Are Kids More At Risk for Epsilon?

There is little data currently available about the risk of the B.1.427 and B.1.429 variants in children. However, there is no evidence suggesting these variants cause more severe disease in children and does not suggest increased infection among children. 

A Word From Verywell

Even though the B.1.427 and B.1.429 variants of COVID-19 are declining in the United States, experts are still concerned about their spread in the U.S. and the world. As these variants are more contagious, they have the opportunity to spread quickly.

Following precautions as outlined by the CDC and getting a vaccine when it is available to you are important to help decrease the spread of these 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.