India's COVID-19 variant: What we know so far

Veronica Hackethal, MD
Dubbed the "double mutant" variant and announced barely one month ago, already researchers are trying to figure out whether it could be causing the surge in cases -- and what that could mean for the rest of the world.
"We need to keep a close eye on this variant," Katelyn Jetelina, PhD, MPH, of the University of Texas Health Science Center at Houston, wrote in a recent email newsletter.
Why "Double Mutant"?
Its official name is B.1.617, and the "double mutant" is a bit of a misnomer, because it actually carries 13 mutations, 7 of which are in the spike protein. But the moniker comes from two notable mutations found in other variants that appeared together for the first time in this new strain: the L452R mutation and the E484Q mutation.
The L452R mutation in the spike protein was first found in the COVID-19 variant detected in California. One study found that the California variant carrying this mutation may be up to 20% more transmissible than wild-type strains.
The E484Q mutation is notable because it appears to be very similar to the E484K mutations found in the B.1.351 (South African) and P.1 (Brazilian) variants. The E484K mutation in these variants is considered an "escape mutation" because it enables SARS-CoV-2 to evade immune protection with monoclonal antibodies, which may decrease the effectiveness of vaccines. So far, though, current vaccines appear to be holding up against these variants, according to Jetelina.
The exact significance of these mutations is still being worked out.
"Just because there are two worrisome mutations on one variant doesn't necessarily mean this is [doubly] contagious or [doubly] deadly. The WHO [World Health Organization] has declared B.1.617 a 'Variant of Interest' instead of a 'Variant of Concern,'" she wrote.
WHO defines a "variant of interest" as one that has been found to cause community transmission, has been found in multiple COVID-19 cases or clusters, or has been found in multiple countries.
(To be contd)