A new variant of Covid-19 named “Arcturus” is behind a fresh surge of infections in India.
The Omicron sub-variant XBB.1.16 strain is on the verge of devastating the country where cases have soared 13-fold in the last month.
India's health ministry launched mock drills this week in an attempt to see if hospitals are prepared to deal with a possible influx of patients following the rise in cases.
Wearing face coverings in public has been made compulsory again in some states, being the first time in more than a year.
The World Health Organization (WHO) is currently monitoring Arcturus, also known as XBB.1.16, which was first detected in late January, with officials saying it had some mutations of concern.
Dr Maria Van Kerkhove, the WHO's Covid technical lead, said: “It's been in circulation for a few months.
“We haven't seen a change in severity in individuals or in populations, but that's why we have these systems in place.
“It has one additional mutation in the spike protein which in lab studies shows increased infectivity as well as potential increased pathogenicity.”
Dr Van Kerkhove added that while XBB.1.16 had been detected in other countries most sequences were from India where it had replaced other variants.
In the southern state of Kerela health minister Veena George reintroduced masks for the elderly, pregnant women, and those with underlying conditions.
This week, case numbers throughout India rose by 3,122 in a single day.
It comes as the country's ministry of health recorded 40,215 active Covid infections on 12 April.
Officials are now urging states to increase testing for the virus.
Virologist Professor Lawrence Young from the University of Warwick told The Independent that the rise of the new variant in India is a sign that “we’re not yet out of the woods.”
“We have to keep an eye on it,” Professor Young said. “When a new variant arises you have to find out if it’s more infectious, more disease-causing, is it more pathogenic? And what’s going to happen in terms of immune protection.
“These kinds of things highlight the importance of genomic surveillance but a lot of countries including our own have let our guards down a bit and we can’t be sure what variants are around and what level of infection they’re causing until we see a significant outbreak.”
India was devastated by the Delta wave in 2021 with a total of 4.7 million excess deaths according to WHO estimates.
India's health system was overwhelmed by a surge of cases triggered by that Covid variant with some hospitals even running out of oxygen.