Lambda, which is also known as the C.37 variant, is responsible for 1,037 cases of COVID-19 in the U.S., according to data from the GISAID Initiative, which promotes the rapid sharing of information about influenza and coronaviruses.
The variant was first identified in Peru in August, 2020, where it has now become the dominant strain of the virus, and it has been reported in 29 countries including the U.S.
Researchers at the University of Tokyo published their paper at bioRxiv, a “preprint server for biology,” last Wednesday ahead of the paper’s peer review.
In lab experiments, they identified three mutations in the Lambda variant’s spike protein—called RSYLTPGD246-253N, 260 L452Q and F490S—that make it more resistant to neutralization by antibodies that are induced through vaccination. This makes the strain more resistant to vaccines than the original COVID-19 strain first identified in Wuhan, China
The research team also identified two further mutations—T76I and L452Q—that make the Lambda variant highly infectious. They also warn that the World Health Organization’s classification of Lambda as a Variant of Interest (VOI) rather than a Variant of Concern (VOC) might lead some people to take the threat less seriously.
The researchers write: “Because the Lambda variant is a VOI, it might be considered that this variant is not an ongoing threat compared to the pandemic VOCs.”
“However, because the Lambda variant is relatively resistant to the vaccine-induced antisera, it might be possible that this variant is feasible to cause breakthrough infection,” the paper says.
“Vaccine-induced antisera” refers to the antibodies that arise from vaccination.
The graphic below, provided by Statista, shows the seven-day rolling average of newly confirmed COVID cases per million people in the U.S. and E.U.
Senior researcher Kei Sato told Reuters: “Lambda can be a potential threat to the human society,” echoing the language of the paper he co-authored, which called Lambda and three other VOIs “potential threats” to society. Those three other variants are Eta, Iota and Kappa.
Dr. Pablo Tsukayama, a molecular microbiologist at Cayetano Heredia University in Lima, Peru, and one of the people who helped document Lambda, told Al Jazeera on July 27: “When we found it, it did not attract much attention.”
“But we continued processing samples, and by March, it was in 50 percent of the samples in Lima. By April, it was in 80 percent of the samples in Peru,” he said.
“That jump from one to 50 percent is an early indicator of a more transmissible variant,” Tsukayama added.
Newsweek has asked the Centers for Disease Control and Prevention (CDC) for comment.