As COVID-19 cases overwhelm hospitals in India, a new coronavirus variant has emerged.
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. In contrast, a “variant of concern” is defined as one that has been associated with or has demonstrated increased transmissibility, increased virulence, a change in clinical disease, or decreased effectiveness of efforts to control or treat the illness.
Why Is the ‘India’ Variant Important?
B.1.617 has been spreading quickly in India. It is now the dominant strain in the state of Maharashtra in southwestern India. Maharashtra is India’s second most populous state and home of India’s financial center at Mumbai.
Back in December 2020, 271 million people (about one-fifth of India’s population) were already infected with COVID-19. Modelling studies suggested that India may have already reached herd immunity through natural infection. India’s health minister announced that the country had successfully contained the spread of the virus.
Three months later, India is battling its biggest COVID-19 surge yet. Infections are at the highest daily average reported, with over 340,000 new infections reported daily, and experts believe the actual number of infections and deaths may be under-estimated.
Could the new variant be to blame for the current surge? Or is it a confluence of factors related to people letting their guard down — a lack of masking, large gatherings of people mixing and travelling together, and people somehow thinking that India was already immune?
No one really knows, but a similar situation has already occurred elsewhere in the world.
“We saw the same story in Brazil. The city of [Manaus] had over 70% of people ‘naturally’ infected. But, once P.1. hit, they had a major surge,” Jetelina wrote. “Populations that have high ‘natural’ immunity are getting re-infected. It doesn’t look like natural infection will protect us for long. Get your vaccine.”
Implications for Pandemic Control
On April 3, a patient in the San Francisco Bay area became the first confirmed case of the B.1.617 variant in the U.S. The variant has since been found in 18 other countries and on all continents, except Africa.
Preliminary evidence so far suggests that the Covaxin vaccine is still protective against the double mutant variant. Covaxin is an inactivated vaccine that contains killed coronavirus material and is made in India. Scientists in India have also reported that Covishield, which uses the same biotechnology as the AstraZeneca vaccine, has efficacy against the mutant.
Still, Jetelina urged vigilance: “The more this virus jumps from person-to-person (regardless of where it’s at in the globe), the more chances it has to mutate,” she wrote. “The more it mutates, the more chances it has to outsmart our vaccines.”