Coronavirus US: what is the Lambda variant? Is it in the United States?

While the delta variant of the coronavirus has quickly become the dominant strain in the United States, it's not the only variant circulating.

Lambda variant

The Lambda variant, first identified in Peru, is also beginning to make headlines as it has started to be identified in several states. Infections caused by the Lambda variant have been emerging in the United States, including in Texas, where Houston Methodist Hospital last month reported its first case. Scientists at the Medical University of South Carolina recently announced they had found the variant in a virus sample taken in April.

What do we know about Lambda

Dr. Stuart Ray is a professor of medicine at the Johns Hopkins Hospital, where he specializes in infectious diseases. Ray opened one of the first covid-19 wards at Johns Hopkins in March 2020, and he has also overseen Johns Hopkins' covid-19 sequencing efforts. He told NPR that Lambda is "sort of a cousin of the alpha variant" - one of the earliest identified variants of concern.

Genomic sequencing has identified 1,060 cases of covid-19 caused by the Lambda variant in the United States so far, according to the independent data-sharing initiative GISAID. While that number is a far cry from the surge in cases caused by the Delta variant, representing about 83% of new cases in the US, infectious disease experts have said that Lambda is a variant they are watching closely.

"Variant of concern"

In a paper posted on bioRxiv ahead of peer review, the researchers warn that with Lambda being labeled a "Variant of Interest" by the World Health Organization, rather than a "Variant of Concern," people might not realize it is a serious ongoing threat.

"I think any time a variant is identified and demonstrates the capacity to rapidly spread in a population, you have to be concerned," Dr. Gregory Poland, a professor of medicine and director of the Vaccine Research Group at the Mayo Clinic in Rochester, Minnesota, told CNN.

"There are variants arising every day, if a variant can be defined as new mutations," he said. "The question is, do those mutations give the virus some sort of advantage, which of course is to human disadvantage? The answer in Lambda is yes."

There is still plenty left to learn about Lambda. Early studies suggest that it has mutations that make it more transmissible than the original strain of the coronavirus.

"Lambda has mutations that are concerning but this variant remains quite rare in the US despite being around for several months," Dr. Preeti Malani, chief health officer in the division of infectious diseases at the University of Michigan, wrote.

"It's difficult to know for certain how transmissible Lambda is and how well vaccines work. So far, it seems that Lambda is more transmissible than the original SARS-CoV-2 virus," which is similar to Delta and other variants, wrote Malani, an expert with the Infectious Diseases Society of America. SARS-CoV-2 is the name of the coronavirus that causes covid-19.

Senior researcher Kei Sato of the University of Tokyo says "Lambda can be a potential threat to the human society."