The Lambda lineage: Facts on the new strain of Sars Cov 2 virus
In the last few months, the Covid pandemic has continued to threaten the world with new, mutated, and more lethal strains being reported now and then. Adding to the already existing woes, scientists have warned about another emerging strain, Lambda.
The Lambda variant has now been found in 29 different countries, seven of them in Latin America and it is the dominant strain in Peru.
As reports about the already dominating Delta strain continue to create havoc across countries, a more recently identified lineage, labeled as a variant of interest by WHO on 15 June 2021, Lambda, has taken the world by storm. In a recent statement, WHO has already affirmed that "lambda has been associated with substantive rates of community transmission in multiple countries, with rising prevalence over time concurrent with increased Covid-19 incidence" and that more investigations would be carried out into the variant.
What is Lambda?
The lambda virus, scientifically denoted as lineage C.37 or the 'Andean' variant, has developed novel mutations within the receptor-binding domain, specifically L452Q and F490S, in the spike protein and has been noted as the 7th variant of interest. Researchers are attributing this mutation as the cause behind its increased transmissibility and have highlighted an increase in susceptibility to re-infection or a reduction in the protection provided by current vaccines. According to a recent pre-print research report, a two-fold increase in infectivity has been identified with Lambda. Yet another study by researchers in Chile has reported that C.37 has greater infectivity than the earlier Alpha and Gamma variants.
Origin and global spread of Lambda-
The lambda virus owns its origin in Peru in August 2020. With 81 percent of all COVID-19 cases being attributed to it, this strain has been recognized by The health ministry of Malaysia to be deadlier than Delta. Spreading rapidly in South America, updated reports have confirmed eight cases of the C.37 variant in England, UK, all related to overseas travel history. Though cases of C.37 has not yet been detected in India, it has already spread to more than 29 countries including Chile, Argentina, Peru, Ecuador, Brazil, Colombia, U.S., Canada, Germany, Spain, Israel, France, the U.K., and Zimbabwe, among others, although in small clusters. In Asia, only Israel has reported this variant until now.
Is Lambda immune to vaccines?
With ongoing research in its initial stages, scientists believe that it's too early to put forth any evidence-backed data on the infectivity of the new strain, while at the same time highlighting that the multiple mutations can potentially lead to increased transmissibility or increased resistance to the antibodies through vaccines.
According to a yet-to-be-published study article, the Pfizer and the Moderna mRNA coronavirus vaccines are still effective against this variant, further elaborating that there was a "partial resistance to neutralization", however, this "is not likely to cause a significant loss of protection against infection" in vaccinated individuals. CoronaVac, a vaccine made in China, is facing controversies as questions arise on its efficacy after research results from Chile have revealed that mutations present in the spike protein of Lambda confer increased infectivity and immune escape from neutralizing antibodies elicited by CoronaVac.
"There is currently limited evidence on the full extent of the impact associated with these genomic changes, and further robust studies into the phenotype impacts are needed to better understand the impact on countermeasures, and to control the spread," WHO said in a statement. "Further studies are also required to validate the continued effectiveness of vaccines."
The Indian government is closely monitoring the global course of the new strain and has assured that any new case of C.37 will be identified immediately by INSACOG (The Indian SARS-CoV-2 Consortium of Genomics). Having said that, it is high time that India, still battling with the second wave, needs to continue following all Covid-appropriate-behavior strictly to avoid a resurgence of new cases that may ultimately trigger a more lethal third wave.