Lambda variant cases of COVID-19 are emerging in the US. While nowhere near the surge of cases from the Delta variant yet, it is being watched closely by infectious disease experts. The Lambda variant has been designated as a “variant of interest” (as opposed to “variant of concern” for the Delta variant) by the World Health Organization.
Not much is known about the Lambda variant at the time. In the US, the Lambda variant is not as concerning as the Delta variant, as cases have remained relatively rare despite months having passed since the first case was identified. Still, early studies have shown that the variant possesses mutations that make it more transmissible than the original variant, similar to other variants, such as the Delta variant. The degree to which the variant is transmissible, and the effectiveness of the COVID-19 vaccines against the variant, has not yet been determined.
Some studies show that the vaccine is still effective against the Lambda variant, but further study is necessary as the data is contradictory. A recent lab study written up by researchers in July provided some evidence that a booster shot for individuals that received the single dose Johnson & Johnson vaccine would better protect them against the virus. However, the study was a lab study-- which does not reflect real world effects-- and was not peer reviewed carefully. A study completed at the New York University Grossman School of Medicine revealed that some new variants may be resistant to the J&J vaccine. Researchers believe that a booster dose may help provide further protection. Variants Beta, Delta, Delta plus, and Lambda showed some resistance to the antibodies produced by the Pfizer/BioNTech and Moderna vaccines. Conclusions have been drawn that the vaccines are still effective against the aforementioned variants. A preprint paper from scientists in Japan found three mutations in the spike protein of the Lambda variant that might resist the immunity created from vaccines. However, this paper has not been published in a peer reviewed journal.
Experts continue to stress the importance of vaccination and social distancing to prevent the spread of new variants, as reducing the overall number of COVID-19 cases is the best way to prevent the spread of new variants. While the Lambda variant is of relatively low concern in the US, large numbers of unmasked and unvaccinated individuals will spread the virus faster and create a higher possibility of a variant resistant to vaccines completely arising.