COVID-19 India variant: What scientists know so far amid crisis in subcontinent

NEW DELHI — India has recorded the world’s sharpest spike in coronavirus infections this month, with more than 366,000 new daily cases reported on Monday. Scientists are studying what led to the unexpected surge, and particularly whether a variant of the novel coronavirus first detected in India is to blame.

The variant, named B.1.617, has been reported in at least 17 countries, raising global concern.

Here are the basics:

Two key mutations

The B.1.617 variant contains two key mutations to the outer “spike” portion of the virus that attaches to human cells, said senior Indian virologist Shahid Jameel. The World Health Organization (WHO) said the predominant lineage of B.1.617 was first identified in India in December, though an earlier version was spotted in October 2020.

On May 10, the WHO classified it as a “variant of concern,” along with variants first detected in Britain, Brazil and South Africa. Some initial studies showed that the India variant spreads more easily. “There is increased transmissibility demonstrated by some preliminary studies,” Maria Van Kerkhove, WHO’s technical lead on COVID-19, said, adding that more information was needed to understand how much of the India variant is circulating.

The variant has already spread to other countries, and many nations have moved to cut or restrict movements from India.

Complicated picture

According to the WHO, while laboratory-based studies of limited sample size suggest increased transmissibility of the India variant, the picture is complicated because the highly transmissible B.117 variant first detected in the UK is behind spikes in some parts of India.

In New Delhi, UK variant cases almost doubled during the second half of March, according to Sujeet Kumar Singh, director of the National Centre for Disease Control. The India variant, though, is widely present in Maharashtra, the country’s hardest-hit state, Singh said.

Prominent US disease modeler Chris Murray, from the University of Washington, said the sheer magnitude of infections in India in a short period of time suggests an “escape variant” may be overpowering any prior immunity from natural infections in those populations. “That makes it most likely that it’s B.1.617,” he said.

But Murray cautioned that gene sequencing data on the coronavirus in India is sparse, and that many cases are also being driven by the UK and South African variants.

Carlo Federico Perno, head of microbiology and immunology diagnostics at Rome’s Bambino Gesù Hospital, said the India variant couldn’t alone be the reason for India’s huge surge, pointing instead to large social gatherings. Prime Minister Narendra Modi has been criticized for allowing massive political rallies and religious festivals, which have been superspreader events in recent weeks.

Protective vaccines

Soumya Swaminathan, WHO chief scientist, said studies were under way in India to examine the variant’s transmissibility, the severity of disease it causes and the response of antibodies in people who have been vaccinated.

“What we know now is that the vaccines work, the diagnostics work, the same treatments that are used for the regular virus work, so there is really no need to change any of those,” Swaminathan said.

White House chief medical adviser Anthony Fauci said that preliminary evidence from lab studies suggests that Covaxin, a vaccine developed in India, appears capable of neutralizing the variant.

Public Health England said it was working with international partners but that there is currently no evidence that the India variant and two related variants cause more severe disease or render less effective the vaccines currently deployed.

“We don’t have anything to suggest that our diagnostics, our therapeutics and our vaccines don’t work. This is important,” said Van Kerkhove.