Compared to other coronavirus variants, not much is known about lamda — the strain spreading through South America first detected in Peru in August 2020.
Here are seven things to know about the variant:
1. The World Health Organization classified the strain as a variant of interest June 14, meaning it has genetic changes that are predicted or known to "affect virus characteristics such as transmissibility, disease severity, immune escape, diagnostic or therapeutic escape," and has caused "significant community transmission or multiple COVID-19 clusters" across multiple countries.
2. Lambda has been detected in 29 countries, territories or areas in five WHO regions, with the strongest presence in South America as of June 15.
3. Eighty percent of all cases sequenced in Peru since April were linked to the variant, according to a June 15 WHO report. In Chile, 31 percent of cases sequenced to date are associated with lambda.
4. The variant has been detected in less than 1 percent of samples sequenced in the U.S., according to The New York Times, which cited data from GISAID — which tracks global viral genome data.
5. The variant carries several mutations seen in other strains, including seven in the spike protein. While they have the potential to make the strain more infectious or make it more able to resist neutralizing antibodies, further study is needed, the WHO said.
6. There is not much data on how the variant may affect vaccine efficacy, especially for the vaccines approved for use in the U.S. That's because in South America, Chinese COVID-19 vaccines Sinovac and Sinopharm are more widely distributed in the region.
7. Preliminary lab studies have found antibodies generated by the Pfizer and Moderna mRNA vaccines are less powerful against lambda compared to the original strain, though still able to neutralize it, the Times reports. Still, experts say real-world studies are needed to better grasp how well vaccines stack up against lambda.
"I don't think it's going to be worse than any of the ones that we have already," said Pablo Tsukayama, PhD, a microbiologist at Cayetano Heredia University in Peru who documented Lambda's emergence. "It's just that we know so little that it lends itself to a lot of speculation," he told the Times.