How worried should you be? We asked top researchers.

A new COVID-19 variant that is thought to be behind rising COVID-19 cases in India has just been detected in California's Bay Area. The Stanford Clinical Virology Lab identified the so-called "double mutant" variant through genomic sequencing of coronavirus tests, according to the San Francisco Chronicle.


India's Ministry of Health labeled the variant as a "variant of concern" in late March. This particular variant, which Indian health officials called a "double mutant" in a news release, has two mutations in the spike protein of SARS-CoV-2, the virus that causes COVID-19, and has caused about 20% of new cases in India's Maharashtra region. "Such mutations confer immune escape and increased infectivity," the release said. "These mutations have been found in about 15-20% of samples and do not match any previously catalogued variants of concern." The Ministry of Health also said that officials in India are "continuing to further analyze the situation."

It's understandable to have questions after hearing this news. Is the double mutant variant more contagious that other types of COVID-19, and are you protected against it if you've had the vaccine? Here's what you need to know.

First, what is a double mutant COVID variant?

Just a quick recap: A variant is a change from a virus' original form. Viruses constantly change through mutation, and new variants of any virus—including COVID-19—are expected, according to the Centers for Disease Control and Prevention (CDC). Sometimes new variants pop up and disappear, and other times they persist and spread.

This new COVID variant is called a "double mutant" because "it has two mutations that researchers are interested in that are in the spike protein," infectious disease expert Amesh A. Adalja, MD, senior scholar at the Johns Hopkins Center for Health Security in Maryland, tells Health. The spike protein in SARS-CoV-2 is what the virus uses to latch onto your cells and replicate, he explains. (This particular variant contains the E484Q and L452R mutations, if you want to get really technical.)

What's unclear right now is whether the double mutant strain only has those two mutations—or if they're just the ones that researchers are interested in at this point.

How concerned should you be about the double mutant COVID variant?

The CDC has a special list of variants that the organization is keeping an eye on, with labeling to indicate how concerned the CDC is about any particular variant.

Right now the CDC lists variants like B.1.1.7, P.1 and B.1.351 as "variants of concern," which means they have evidence of being more contagious and causing more severe disease than the original SARS-CoV-2. However, this double mutant variant isn't on the list. Or, at least, it isn't on the list yet.

"At this point we don't know yet how concerning this double mutant is," Timothy F. Murphy, MD, senior associate dean for clinical and translational research at the University at Buffalo, tells Health. "Cases are increasing in India, but they're not spreading rapidly."

"Should we be concerned about this? Yes. But how much is unclear right now," he says.

It's worth noting, though: This isn't the only variant out there with two mutations. "Typically a variant has more than one mutation," William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells Health. That's especially true if a virus spreads more easily than others, which are usually the variants that scientists are the most interested in. In other words, the double mutant variant isn't technically the only double mutant variant out there—it's just a term that's been used to describe it.

Do the vaccines work against the double mutant COVID variant? What about treatments?

As of now, it doesn't seem like the double mutant variant lowers the effectiveness of vaccines or treatments, Dr. Schaffner says. However, he points out, it is more contagious than the original SARS-CoV-2. "It's going to make a contribution in creating more cases," he says. "Please, everyone, let's keep our masks on and [keep] social distancing while we're getting vaccinated."

Dr. Schaffner says the fact that the double variant made its way to the US from India shows the importance of vaccination on a global scale. "These variants can occur abroad and be imported into the United States," he says. "We have to vaccinate not only everyone in the US, but we're going to have to make a larger contribution to the reduction of the pandemic around the world. Otherwise, we'll keep having variants introduced back into this country."

While experts say it's a good idea to keep practicing COVID-19 precautions, they agree that people shouldn't panic over the double mutant COVID variant.

"There are tons of variants out there," Dr. Adalja says. "It's too early to say what the importance of this particular one will be."

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDCWHO, and their local public health department as resources.

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