Coronavirus lambda variant spreads across Latin America

World Friday 25/June/2021 05:04 AM
By: DW
Coronavirus lambda variant spreads across Latin America
The number of COVID-19 dead in Peru is far higher than reported, it emerged in June

Berlin: Classified as a "variant of interest" by the World Health Organization (WHO) on June 17, the lambda, or C.37, variant of the coronavirus has already been detected in 29 nations — seven of them in Latin America. In Peru, where it was identified in August, the lambda variant now accounts for 82% of new infections, and it is also being found in one in three confirmed cases in Chile. It is also spreading rapidly in Argentina, Brazil, Colombia, Ecuador and Mexico.

"So far we have seen no indication that the lambda variant is more aggressive," the WHO virologist Jairo Mendez-Rico told DW. "It is possible that it may exhibit higher infection rates, but we don't yet have enough reliable data to compare it to gamma or delta."

Alpha (B.1.1.7), beta (B.1.351) delta(B.1.617.2) and gamma (P.1) are categorized as "variants of concern" by the WHO. The classification indicates that they are more transmissible and more difficult to treat and can lead to more serious illness.

"Although it is possible, currently there is no indication that variants are more dangerous and lead to increased mortality," Mendez-Rico said. "It is likely that SARS-CoV-2 will become more transmissible throughout the course of its evolution but not necessarily more damaging to the host."

Peru's high toll

The virologist Pablo Tsukayama and his team at Lima's Cayetano Heredia University have traced the evolution of the lambda variant in Peru for months after identifying it through genome testing. It spread more quickly than variants deemed far more dangerous by the WHO out of the way, even prevailing over the gamma variant, which had run rampant in neighboring Brazil.Many scientists believe that the coronavirus pandemic won't be over until at least 80% of the world's population has been vaccinated. Variants like lambda could continue to emerge until that is achieved.

Mendez-Rico said inoculation presented the most effective defense: "All of the vaccines we have approved worldwide have been generally effective against circulating coronavirus variants, and there is no reason to suspect them to be less so against lambda."

"We had 200 lambda infections in December," Tsukayama said. "By the end of March, it made up half of all samples taken in Lima. Now, three months later, we are looking at more than 80% of all infections nationwide. Lambda has become the dominant variant in Peru in a very short period of time."

Tsukayama said lambda was more transmissible, which had helped it spread so quickly in Peru: "With 187,000 dead and the highest mortality rates in the world, we are the country that has struggled most when it comes to the coronavirus. Therefore, it is probably no wonder that the new variant has gotten its start here."

Epicentre for variants?

Latin America — with more than 1 million coronavirus deaths already — could become the new epicenter of coronavirus variants. In Colombia, for instance, the highly contagious B.1.621, a variant of interest first detected there in January, is increasingly spreading.

The combination of overwhelmed health care systems, populations working precarious jobs without much opportunity to adhere to safety precautions, and a lack of vaccines have proven a perfect breeding ground for the lambda variant.

"Chile has vaccinated 60% of its citizens, but that is an exception on the continent," Tsukayama said. "It is very likely that new variants will appear during a third wave of coronavirus infections during the South American winter between July and September. They may not be any more lethal but they will definitely be more communicable."