There has been a lot of discussion and some sensational headlines surrounding a new SARS-CoV-2 variant of interest: the Lambda variant. So, what do you need to know about it?
The Lambda variant made its way onto the World Health Organization’s (WHO) “variant of interest” watchlist on June 14, 2021. This means the virus shows genetic changes that are predicted or known to affect its transmissibility, disease severity, immune escape, etc, and it’s caused a significant number of infections.
It’s not yet considered a “variant of concern,” which means variants that have undergone genetic changes to such a degree it will affect the global shape of the pandemic, such as the better-known problematic variants Alpha, Beta, Gamma, and Delta.
Named after the 11th letter of the Greek alphabet, the Lambda variant has now been found in at least 27 different countries after first being detected in Peru in December 2020. A WHO report from June 15, 2021 [PDF] explains that the Lambda variant has been responsible for significant rates of community transmission in multiple countries, especially in Chile, Peru, Ecuador, and Argentina. Authorities in Peru reported that 81 percent of COVID-19 cases sequenced since April 2021 were associated with the Lambda variant. England has also reported six cases of the variant, all of which have been linked to overseas travel, according to Public Health England as of June 2.
The spike protein of the Lambda variant features novel mutations, called L452Q and F490S, within the receptor-binding domain, which is the “key” used by the virus to bind and gain entry into host cells.
The current concern around this variant is whether these key mutations will affect the efficacy of the COVID-19 vaccines. Two preliminary studies, which are yet to be peer-reviewed, have weighed in on this question, both of which come to different conclusions (and need further research to verify).
The first paper, posted on the health sciences preprint server medRxiv on June 1 by scientists at the University of Chile, Santiago, concluded that the mutations present in the spike protein of the Lambda variant of interest make it less susceptible to antibodies elicited by CoronaVac, the Chinese vaccine that’s been widely used in Chile. Meanwhile, a second paper posted two days later by the New York University Grossman School of Medicine found the opposite, concluding “vaccines in current use will remain protective against the lambda variant.”
For now, it’s still too early to draw any rock-solid conclusions about the Lambda variant and its potential for breakthrough infection. However, it appears this variant is something scientists and health authorities will certainly keep a close eye on.