Data suggests the variant has been in the US since April 2021, when it was discovered after an outbreak in a Kentucky nursing home.

Advertisement

The World Health Organization recently announced the Delta variant has surpassed other mutations of SARS-CoV-2 as the most prominent strain in the world—but researchers have identified another strain, the R.1 variant, that's been responsible for a small number of COVID-19 cases in the United States and worldwide.

What Is the R.1 COVID Variant? Here's What We Know So Far , Corona virus digitally generated image on white background

The R.1 variant of SARS-CoV-2, the virus that causes COVID-19, isn't new: The mutation was first detected in Japan last year, and it's since made its way to other countries, including the US. In fact, a Morbidity and Mortality Weekly Report from the Centers for Disease Control and Prevention (CDC), dated April 21, suggests the mutation has been present in the United States as early as April 2021, and that it was in part responsible for an outbreak among nursing home patients in Kentucky earlier this year.

When the Kentucky Department of Health and a local health department investigated a COVID-19 outbreak of vaccinated patients in a skilled nursing facility, they found the R.1 variant during genome sequencing—suggesting this mutation may be more likely to cause breakthrough infections than past strains. So far, the R.1 variant has been detected in 47 US states and is linked to 2,259 cases, according to reporting by Newsweek.

Here's what you need to know about the R.1 COVID-19 variant and how to protect yourself from it, according to infectious disease experts.

What's the R.1 variant, and should we be worried about it?

According to Amesh A. Adalja, MD, a senior scholar at Johns Hopkins Bloomberg School of Public Health's Center for Health Security, the R.1 variant is a version of the SARS-CoV-2 virus that has mutations associated with changes in the function of the virus. In other words, as with any new strain, R.1 could affect people differently than the original version of the virus.

That said, identification of a new strain isn't necessarily cause for panic. While any new variant can pose a threat, Dr. Adalja says it's unlikely the R.1 variant will overtake the Delta variant as the most severe or transmissible mutation of the SARS-Cov-2 virus.

"I don't suspect it will be a major problem because it doesn't have the ability to displace Delta," he says. "It's really hard for these types of mutations to get any foothold in a country that has the Delta variant present."

While Dr. Adalja doesn't necessarily expect any different symptoms from this strain, he says it could potentially affect more people who are vaccinated against COVID-19. "The issue is this mutation does have mutations we saw with the B and G variants people forgot about," he says. "That may make breakthrough infections more common, but it's not about that." How rampant a strain becomes, Dr. Adalja emphasizes, has more to do with its transmissibility—and, again, it's pretty unlikely this one will displace the Delta variant.

Currently, the R.1 variant only accounts for 0.5% of COVID-19 cases in the US and worldwide; according to Ramon Lorenzo Redondo, PhD, research assistant professor of infectious diseases at Northwestern University Feinberg School of Medicine, the R.1 mutation hasn't been sequenced—or genetically identified—in a US case since early August. "This version of the virus never accounted for more than 1% of worldwide cases, even at its peak," Redondo says.

What's the best way to stay safe from the R.1 variant?

All the same safety measures that applied before still apply when a new strain is identified. "There will be many new variants just like this one," Dr. Adalja says. "What's important to remember about all these is that it's hard for them to do anything on a grand scale when the country is already so bathed in the most fit version of the virus."

According to Redondo, the best way to keep yourself safe from Delta, R.1, or any strain of SARS-Cov-2, is to get fully vaccinated and to continue practicing CDC-recommended precautions, such as masking in public. Protecting yourself from getting infected is also the most effective method for stopping the virus from continually mutating.

"The only way to stop new variants is to stop the number of infections," Redondo says. "If you drive the population to very low numbers and the diversity is constricted, the virus can't evolve as much."

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.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter