The B.1.617 coronavirus variant has been identified in at least 49 countries since emerging in India late last year, reports The New York Times.
Seven things to know about the variant:
Emergence
1. The B.1.617 coronavirus variant was first identified in India last December and is now the country's dominant strain.
2. The variant carries two virus mutations. One is the same mutation found in another variant first detected in California, which is 20 percent more transmissible than existing strains, according to the CDC. The other mutation has been seen in variants first detected in Brazil and South Africa.
Prevalence in U.S.
3. The U.S. has detected more than 800 COVID-19 cases involving the variant since it was found in the U.S. between late February to March 2020, according to The Seattle Times and The New York Times.
4. The B.1.617.2 form of the variant accounts for just 0.5 percent of all COVID-19 cases in the U.S., while the B.1.617.1 form accounts for 0.2 percent, according to CDC estimates through April 24.
Classification
5. The World Health Organization declared B.1.617 a "variant of concern" May 10, citing preliminary studies showing the variant is more transmissible than existing strains.
6. The CDC classifies three forms of the B.1.617 strain as "variants of interest." The agency is now assessing whether to escalate this designation, CDC spokesperson Jade Fulce told The Seattle Times.
Transmissibility
7. Government scientists in the U.K. have said it's "highly likely" that the B.1.617 variant is more transmissible than the B.1.1.7 variant first found in the U.K., according to The New York Times. It's not clear whether the India variant is more deadly than the U.K. variant.
8. The U.K.'s Scientific Advisory Group for Emergencies has said the India variant could be up to 50% more transmissible than the U.K. variant, though research is still preliminary.
Vaccine efficacy
9. Pfizer-BioNTech's and AstraZeneca's COVID-19 vaccines are effective against the B.1.617.2 form of the variant, according to research released May 22 by Public Health England. Pfizer's vaccine was 88 percent effective against symptomatic infection from the variant two weeks after the second dose. For comparison, the vaccine is 93 percent effective against the B.1.1.7 variant.