India is grappling with a devastating second wave of coronavirus that’s far more fatal than the first — and scientists say the surge could be partially due to mutating strains.

The World Health Organization just reclassified the B.1.617 strain, which was first identified in India, as a “variant of concern” — which indicates that the variant has the “highest public health implications.”

India is the world’s second worst hit country, reporting more than 22.66 million infections and more than 246,000 deaths to date, data from India’s health ministry shows. Experts say the numbers are likely severely underreported as many never make it to the hospitals which have run out of beds and oxygen.

What do we know?
The earliest samples of the B.1.617 were detected in India in October, and authorities announced in March this year that the variant had become more common in the state of Maharashtra.

The World Health Organization said Monday that it is reclassifying the strain as a “variant of concern.” It was previously named a “variant of interest,” which is a lower level of alert.

Dr. Maria Van Kerkhove, Covid-19 technical lead at the WHO, said there is information suggesting that B.1.617 has “increased transmissibility” and “some reduced neutralization.”

Variants of concern are more contagious, cause more severe disease or reduce the effectiveness of public health measures, vaccines or medication, according to the UN health agency.

“We don’t have anything to suggest that our diagnostics, our therapeutics and our vaccines don’t work,” she said at a media briefing on Monday.

Other variants of concern include the B.1.1.7 which was first identified in the United Kingdom, and the B.1.351 which was discovered in South Africa.