While Indian hospitals buckle under COVID cases and even capacity for cremations runs out, a new ‘double mutant’ variant of the virus has emerged.
First announced just one month ago, scientists are already trying to determine if it is driving the surge in Indian cases — and the implications 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.
What ‘double mutant’ means
Officially named B.1.617, the ‘double mutant’ is a bit of a misnomer, because it actually carries 13 mutations, 7 of which are in the spike protein. The nickname comes from two notable mutations found in other variants that appeared together for the first time in this new strain: the L452R and the E484Q mutations.
The L452R mutation in the spike protein was first found in the COVID variant detected in California, which could be up to 20% more transmissible than wild-type strains.
The E484Q mutation seems very similar to the E484K mutations found in the B.1.351 (South African) and P.1 (Brazilian) variants. These are ‘escape mutations’ because it enables these SARS-CoV-2 variants to evade immune protection with monoclonal antibodies, potentially making vaccines less effective. Thus far, 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.
The WHO definition of ‘variant of interest’ is one that has been found to cause community transmission, has been found in numerous COVID cases or clusters, or has been found in multiple countries. A ‘variant of concern’ on the other hand is defined as one that has been associated with or has demonstrated increased transmissibility, increased virulence, a change in clinical disease, or decreased effectiveness in treating or controlling the illness.
What is the significance of this variant?
The B.1.617 variant has spread rapidly in India, becoming the dominant strain in the state of Maharashtra in southwestern India. Maharashtra is India’s second most populous state and also home to India’s financial centre in Mumbai.
In December 2020, 271 million people (about one-fifth of India’s population) were already infected with COVID, and modelling studies suggested that natural infection had already caused India to reach herd immunity. In light of this, India’s health minister announced that the country had successfully contained the spread of the virus.
Yet three months later, the biggest COVID surge yet is happening in India, with a new high of over 340 000 new infections reported daily. Furthermore, experts believe the actual number of infections and deaths may be under-estimated.
Is the new variant possibly to blame for the current surge? Or is it a combination of factors related to people letting their guard down, such as a lack of masking, large gatherings of people mixing and travelling together, and a belief that somehow India was already immune?
No-one has answers to this yet, 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.”
The variant has been found in the US and 18 other countries and on all continents, except Africa. Preliminary evidence so far suggests that the Covaxin vaccine, an inactivated virus vaccine made in India, is still protective against the double mutant variant. The trial attracted controversy since it was approved in January without a final phase III clinical trial. Scientists in India have also reported that Covishield, which is a viral vector vaccine like AstraZeneca’s jab, has efficacy against the mutant.
Dr Jetelina nevertheless 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.”
Source: MedPage Today
