What's the Deal with the New Strain of COVID-19 from the UK?

The new COVID strain, known as B.1.1.7, is now the "most common" coronavirus variant circulating in the U.S., according to the CDC.

In December, a new and seemingly more contagious strain of SARS-CoV-2, the virus that causes COVID-19, began spreading in the UK. By January, health officials confirmed cases of the variant, known as B.1.1.7, in several other countries, including the U.S. Now, it's the "most common" COVID strain currently circulating in the U.S., Rochelle Walensky, M.D., director of the Centers for Disease Control and Prevention (CDC), said at a recent press briefing.

B.1.1.7 first began spreading in the UK back in December 2020 and has since made its way across Europe. Researchers are still learning more about the variant, but current estimates suggest that the COVID variant from the UK may be roughly 60 percent more contagious than the original form of the virus.

As a result, the CDC now advises U.S. travelers to "avoid all travel" to the UK, even if they've been vaccinated. (

To make matters even more complicated, new COVID-19 variants have also been discovered in South Africa, Brazil, and California. Yes, they're separate from both one another and independent from the UK strain, although all of these new strains appear to have mutations in the virus's spike protein (the part of the virus that binds to receptors in your cells and infects you with COVID-19), according to the CDC. While researchers are still working to understand what's making these COVID variants spread so quickly, experts say these spike protein mutations may have something to do with it. (See: Why Are the New COVID-19 Strains Spreading More Quickly?)

As scary as that all sounds, there's no need to panic just yet. Here's what you need to know about the new COVID strain. (FTR: For the purposes of this story, we'll be discussing the strain discovered in the UK when referencing "the new COVID strain.")


First, know that this isn't the first time we've seen COVID-19 mutations.

In an interview with ABC News, Brett Giroir, M.D., the U.S. assistant secretary of health at the Department of Health and Human Services, noted that there have already been at least 4,000 different mutations among the virus that causes COVID-19 and that researchers have been studying these changes since the beginning of the pandemic.

The most worrying mutations are those that can help the virus evade your immune system or the effects of vaccines and antibody therapies, according to a recent feature published in the scientific journal Nature. (The same holds true for any virus.) So far, researchers haven't identified any of these types of particularly concerning mutations.

A key factor with SARS-CoV-2 B.1.1.7, however, is that it seems to spread more efficiently compared to other known COVID-19 strains, says Robert Amler, M.D., dean of New York Medical College's School of Health Sciences and Practice and former chief medical officer at the CDC.

More specifically, a person infected with this new so-called "UK COVID-19 strain" may spread the virus to, on average, 1.5 people, while someone with a "standard" strain of COVID-19 is expected to infect about 1.1 people, said Maria Van Kerkhove, a technical lead at the WHO, according to U.S. News & World Report. (

Researchers are still trying to understand what, exactly, makes this new COVID-19 variant more transmissible than others. One theory is that this particular strain has become more sustainable in the air, making it easier for the virus to travel from person to person, says Dr. Amler. But, as with so much about this virus, we just don't know enough yet.

In January, a report from UK scientists suggested the B.1.17 variant might carry an increased risk of death compared to other COVID strains, however, more research is needed to confirm whether or not that's the case, according to the CDC.

Is the new COVID-19 strain covered by the vaccine?

As of now, experts seem optimistic about the effectiveness of COVID-19 vaccines against all strains of COVID-19, including the B.1.1.7 variant. "So far, even though we've seen a number of changes and a number of mutations, none has made a significant impact on either the susceptibility of the virus to any of the currently used therapeutics, drugs, or the vaccines under development and one hopes that that will continue to be the case," said Soumya Swaminathan, M.D., chief scientist at the WHO, according to NBC4 Washington. (More here: How Effective Is the COVID-19 Vaccine?)

For context, officials from the WHO also said in a press briefing that, overall, COVID-19 seems to be mutating "at a much slower rate" than the seasonal flu, which is reassuring in terms of the public health response.

"Influenza is notorious for mutating quickly," explains Dr. Amler. "It makes it difficult to immunize against, which is why last year's flu vaccine doesn't work very well against this year's newly mutated flu virus."

But since the SARS-CoV-2 virus doesn't appear to be changing as drastically, there's no reason why it should be resistant to COVID-19 vaccines, including those from Pfizer, Moderna, and Johnson & Johnson, which have already been authorized for emergency use by the FDA, says Dr. Amler. (

The same goes for COVID-19 tests, BTW. "Most commercial polymerase chain reaction (PCR) tests have multiple targets to detect the virus," according to the CDC. Meaning, even if a mutation in the virus impacts one of those targets, "the other PCR targets will still work" to detect COVID-19 in an infected person, reports the agency. (ICYMI: Everything You Need to Know About Coronavirus Testing)

How concerned should you be about the new COVID-19 strain?

The good news is that right now, you can trust the vaccines to be effective in protecting against COVID-19 infection, regardless of the strain. "We don't know that [the new COVID-19 strain is] more dangerous, and very importantly, we haven't seen a single mutation yet that would make [the virus] evade the vaccine," Dr. Giroir told ABC News. "[We] can't say that won't happen in the future, but right now, it looks like the vaccines should cover everything we see." Plus, researchers are continuing to investigate all variants of the virus to determine whether any of them will turn out to be associated with more severe illness or decreased vaccine efficacy, according to the WHO.

Still, with initial analyses suggesting that this new COVID-19 strain may spread more easily than other mutations, experts are urging caution now more than ever. In other words, social distancing, wearing a mask, and washing your hands are still your best bet for avoiding COVID-19 infection and transmission (and getting vaccinated when the COVID-19 vaccine is available to you).

"Mutation or not, we know that this virus is highly contagious and that it can kill," says Dr. Amler. "At this point, everyone knows someone who has caught it and gotten terribly sick or even died. The whole key here is to block exposure. If there is no exposure, there is no infection. It's as simple as that."

The information in this story is accurate as of press time. As updates about coronavirus COVID-19 continue to evolve, it's possible that some information and recommendations in this story have changed since initial publication. We encourage you to check in regularly with resources such as the CDC, the WHO, and your local public health department for the most up-to-date data and recommendations.

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