“Unusual” mutations of Lambda Covid variants puzzle scientists


Lambda is the latest variant of the coronavirus that has caught the attention of the World Health Organization. It worries Latin American officials and confuses scientists because of its “unusual” series of mutations.

The Lambda variant, formerly known as C.37, was first discovered in Peru at the end of last year and has since spread to 27 countries/regions including the United Kingdom. The Department of Public Health England said this week that it has identified it “all over the country”, although the number of confirmed cases is still small.

Pablo Tsukayama, PhD in molecular microbiology from Cayetano Heredia University in Lima, Peru, said that when medical staff first discovered the mutation in December, it “only accounted for one in every 200 samples.”

“However, by March, it accounted for about 50% of the Lima sample, and now it is about 80%. This shows that it has a higher transmission rate than other variants,” he said.

According to the World Health Organization, Lambda accounted for 82% of new Covid-19 cases in Peru in May and June The world’s highest death rate from coronavirusIn neighboring Chile, it accounts for nearly one-third of new cases.

However, scientists are still not sure whether Lambda’s mutation makes it more communicable.

“There is currently no evidence that it is more aggressive than other variants,” said Jairo Méndez Rico, an emerging viral disease consultant at the Pan American Health Organization. “Its infection rate may be higher, but more work needs to be done.”

The WHO named Lambda in June the seventh “variant of interest” to date. The global health agency believes that compared to the four “worrying variants”-Alpha, Beta, Gamma, and Delta originally found in the United Kingdom, South Africa, Brazil, and India, these strains are less threatening, but Said that it still needs to be closely monitored.

A week later, on June 23, the British PHE designated Lambda as the variant under investigation, “due to international expansion and several notable mutations.” PHE emphasized that there is currently no evidence that Lambda can cause more serious diseases or reduce the effectiveness of the vaccine.

Jeff Barrett, Director of Covid-19 Genomics, explained: “One reason it is difficult to understand Lambda’s threat using calculations and laboratory data is that it is quite unusual compared to other variants. A set of mutations.” An initiative of the Wellcome Sanger Institute in the United Kingdom.

Barrett added that Latin America lacks genetic sequencing facilities, so it is difficult to know the extent to which Lambda contributed to the Covid-19 outbreak in the region.

Lambda has a unique pattern of seven mutations in the spike protein used by the virus to infect human cells. Researchers are particularly interested in a mutation called L452Q, which is similar to the L452R mutation, which is thought to contribute to the high infectivity of the Delta variant.

Monica Acevedo of the University of Chile in Santiago and colleagues used blood samples from local medical staff who had received two doses of CoronaVac vaccine from China to study the effects of Lambda on the infectivity of the virus.

Their results were published Preprinted paper On Thursday, it was recommended that Lambda is more contagious than Gamma and Alpha and can better evade the antibodies produced by vaccination. They wrote: “Our data shows for the first time that mutations in the spike protein of the Lambda variant allow neutralizing antibodies to escape and increase infectivity.”

In Brazil, gamma mutations have caused infections so far. A team of researchers at a hospital in the southern city of Porto Alegre analyzed a patient infected with Lambda. “Considering that this variant has spread rapidly in Peru, Ecuador, Chile and Argentina, we believe that Lambda has considerable potential to become a worrying variant,” they concluded in a report. Preprinted paper, This has not yet been peer reviewed.

Latin America is the most severely affected region in the world. It only accounts for 8% of the global population, but it accounts for 20% of coronavirus cases. In recent weeks, the number of cases in Colombia, Paraguay and Uruguay has soared.

“Although we have seen the virus in the northern hemisphere have eased, the end is still a distant future for most countries in our region,” said Karissa Etienne, director of the Pan American Health Organization, this week.

Etienne said that cases in Colombia, Brazil, Bolivia, and Uruguay are still rising, adding that hospitals are working to expand intensive care units.

She said: “Despite the worrisome situation, only one in ten people in Latin America and the Caribbean have been vaccinated against Covid-19-this is an unacceptable situation.”



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