Science

Covid third wave inevitable in India, say health experts


Health experts have warned that a Covid-19 third wave is “inevitable” in India, as evidence grows that new variants are a contributing factor behind the country’s vicious second wave.

India broke global records again on Thursday, recording 412,784 new cases and 3,980 deaths over 24 hours. Experts believe the real figure to be much higher.

K VijayRaghavan, the principal scientific adviser to the Indian government, said at a briefing on Wednesday that the high levels of the virus circulating in India meant “a phase 3 is inevitable” but emphasised he could not give a timeline at this stage.

VijayRaghavan said the government had not expected the “ferocity” of the second wave that has enveloped India over the past few weeks, with devastating consequences. According to the World Health Organization, last week India accounted for 46% of the world’s new coronavirus cases.

VijayRaghavan said there was a high likelihood of new variants emerging in India in the future, which may be more “immune evasive” and transmissible, and that even after this second wave had plateaued, strong disease surveillance and Covid safety measures should remain in place in India.

His cautious warnings were a stark contrast to the government’s messaging at the beginning of this year, after India’s first Covid wave had died down, when “victory” was declared over the pandemic in the country.

There is increasing evidence that new variants are contributing to the devastation in India. Analysis of test samples carried out by the government detected the B1617 variant, known as the Indian variant, in 18 states, as well as the UK B117 variant.

According to early studies, experts and virologists believe the Indian variant may be more transmissible and makes people more susceptible to reinfection, but research is ongoing. The WHO has declared it a “variant of interest”.

Those states where it has been detected include some of the worst-hit regions, including Delhi, Maharashtra, West Bengal, Chhattisgarh and Gujarat.

The Indian B1617 variant appears to be gradually overtaking the UK variant, which has been particularly prevalent in Delhi and northern Indian states such as Punjab.

Sujeet Singh of the National Centre for Disease Control emphasised that while there was growing evidence of the link between the Indian variant and the second wave, “its epidemiological and clinical correlation is not fully established”.

“Without the correlation, we cannot establish direct linkage to any surge,” said Singh. “However, we have advised states to strengthen public health response: increase testing, quick isolation, prevent crowds, vaccinations.”

India has been accused of being slow to sequence Covid-19 samples to detect variants, with only about 1% of samples undergoing genome sequencing. Singh said that since December a total of 18,053 samples had been sequenced so far.

Virologists and Covid modellers have said variants are probably a significant cause of the surge in the virus in India, which has spread unstoppably in big cities and is now devastating rural communities.

Murad Banaji, a mathematician who has modelled India’s Covid pandemic, said his predictions last year had shown a second wave was “highly likely” in India once all lockdowns and restrictions were lifted, but according to data, “it should have been relatively muted in urban centres which had already been hit badly – nothing of the scale that we’ve actually seen.”

According to Banaji’s models, the virus has behaved differently this time round, which could probably be explained by new variants that are more transmissible or able to evade previous immunity.

Banaji added: “The reality is that India was always vulnerable to a new surge, whether or not some more transmissible variants emerged, but the scale and the speed of it, especially in some hard-hit areas such as Delhi and Mumbai, would be hard to explain if you didn’t have variants at play.”

The WHO said recently that the Indian variant had been detected in 17 countries. Fears over its spread have led to multiple countries, including the UK, Australia and Sri Lanka, placing restrictions or outright bans on people flying in from India.



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