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Covid-19 case counts have leapt from the spread of the more infectious Delta version of the SARS-CoV-2 coronavirus. Now, another variant, called Lambda, has reached the U.S., raising fears with its resistance to the immunity conferred by vaccines or synthetic antibody cocktails.
Should the Lambda variant scare you? In a word, no. Research is still preliminary, but while early data show that Lambda is indeed more resistant to antibodies raised against other virus variants, the antibody levels in vaccinated people are more than sufficient to prevent disease symptoms from Lambda exposure.
The Covid virus is constantly evolving, and the Lambda variant was first noted last year in Peru. It is now one of the most common culprits behind new Covid cases in South America. Over 1,000 cases in the U.S. have been tied to the variant. In June, the World Health Organization designated Lambda as “variant of interest”—meaning that it was worth watching, but not the proven threat of “variants of concern” like the infectious Delta.
Lambda has come to the world’s attention because it seems to be both more infectious than the original strain of the SARS-CoV-2 virus and more resistant to current interventions. A study posted July 28 on the website bioRxiv by University of Tokyo researchers reported that Lambda variants have alterations in the virus’s surface spikes that increase their attraction to the entry channels of our cells, while also being harder to recognize by antibodies targeting the spikes of the original virus.
The Tokyo study hasn’t yet been peer-reviewed, but it suggests that antibodies generated by the vaccine from
Pfizer
(ticker: PFE) and
BioNTech
(BNTX) found it almost 1.5 times harder to neutralize Lambda variants than the original virus.
But that doesn’t leave the vaccinated without protection against Lambda. A July 3 study published on the same website by researchers at New York University Medical School tested the variant with antibodies from both the Pfizer-BioNTech vaccine and the vaccine from
Moderna
(MRNA). Compared with the original virus strain, the NYU team found that Lambda was about 3-times more resistant to the Pfizer-BioNTech vaccine antibodies, and 2.3-times resistant to Moderna-generated antibodies. Lambda was also slightly more resistant to the antibodies contained in the cocktail treatment from
Regeneron Pharmaceuticals
(REGN).
Still, Regeneron’s cocktail was able to neutralize Lambda variants well, said the NYU scientists. They also concluded that the average levels of antibodies generated by either the Moderna or the Pfizer-BioNTech vaccines are more than enough to protect against Lambda.
Write to Bill Alpert at william.alpert@barrons.com