Health

Fingers crossed: Experts cautious about variant evolution in the wake of China’s COVID-19 tsunami

Any new variant that emerges from the current surge in China may not have the same lethal ability as past ones. But one cannot rule out possibility of exceptions

 
By Taran Deol
Published: Wednesday 21 December 2022
Union Health Minister Mansukh Mandaviya convened a meeting December 21 in the wake of the COVID-19 surge in China. Photo: @mansukhmandviya / Twitter

Experts are keeping their fingers crossed as China struggles in the maelstrom of its worst COVID-19 wave, recording more than 2,000-3,000 new cases every day for the past week.

Any new variant that emerges from the current surge in China may not have the same lethal ability as past ones. But exceptions are always possible, according to them.

Shahid Jameel, well-known epidemiologist, told Down To Earth (DTE) that it was anybody’s guess as to what kind of variant might emerge from the surge in China.

“No one can predict that. More transmission, more chances. But since the world is heavily vaccinated, one shouldn’t expect the kind of destruction we saw with Delta. Surprises are possible though,” he said.

Anurag Agrawal, dean of the biosciences department at Ashoka University, said the pressure is not on the virus to mutate because of the lack of immunity.

“If you look at last December and now, the total number of omicron infections so far are way more than China’s population. I don’t expect greater mutations from China any more than we have seen in other parts of the world,” he told Down To Earth (DTE).

Since the virus is circulating in a vulnerable population in China, the variant to emerge out of there “may not have the same fitness against hosts with prior infection from other variants of omicron,” Ryan Gregory, an evolutionary biologist and professor at the University of Guelp’s Biodiversity Institute of Ontario in Canada, tweeted.

However, Agrawal also described a low probability event. Human-animal interaction is high in China. The virus can easily jump to animals, mutate further in ways that can’t be predicted right now, and come back into humans.

“This could dictate several changes in the virus’ characteristics which we may not necessarily be prepared for. A One Health approach is needed to tackle the current situation efficiently,” he said.

Robust surveillance and vigilance are critical now more than ever. Particularly in the face of vaccines being unable to prevent infections, and a low booster uptake across the world.

The buildup

Some 60 per cent of China’s population — or 10 per cent of the global population — is expected to get infected with COVID-19 over the coming three months, according to experts.

The surge in China is not unexpected. People have been modelling such a wave for some time.

The most populous country in the world has been an outlier on two key factors — immunity profile and human mindset — until now. This was due to the  uncompromising ‘zero-covid’ policy that the government had put in place.

But the policy was revoked December 7, 2022.

As a result, the omicron strain of SARS-CoV-2 now has perhaps the largest, most immunologically naive population to infect. The scale of such an encounter will give the virus many chances and a vast fertile ground to mutate.

Omicron would have eventually swept through China once restrictions were lifted. It was only a matter of time and whether the outbreak would happen province-wise or all at once.

The omicron sub-variant BF.7 is driving up the caseload in the geography according to local reports. This variant is not fundamentally unique to China.

Vinod Scaria, a scientist at the Council of Scientific and Industrial Research Institute of Genomic and Integrative Biology (IGIB), illustrated China’s layered isolation and how the virus has been evolving.

“While the world has been slowly crawling back to normalcy, suffering huge losses in lives, and learning to live in a pandemic with masks, vaccines, boosters (and) antivirals, and suffering multiple onslaughts/waves of infections, China was isolated in many ways,” Scaria tweeted.

Use of vaccines with poor immunogenicity and immunity built — which is already waning — largely on vaccines and not natural infection are hardly a strong defence against the extremely immune evasive omicron and its sub-lineages, Scaria argued.

A total of 386,276 symptomatic cases have been confirmed in China so far. Models have estimated one million COVID-associated deaths in the wake of the country giving up its zero-COVID policy.

However, its National Health Commission made it clear December 20 that only those dying of respiratory failures will be counted as COVID deaths, excluding anyone with comorbidities who succumbs to the virus, the South China Morning Post reported.

The surge in China has sent jitters globally. The United States as well as India have expressed concerns as to how the virus may evolve in the China outbreak.

The Union Ministry of Health and Family Welfare (MoHFW) wrote to state governments December 20, 2022. It urged them to ramp up genome sequencing efforts of all positive test results.

MoHFW listed the United States, Korea, Brazil and Japan besides China as countries recording a surge in COVID-19.

“Such an exercise will enable timely detection of newer variants, if any, circulating in the country and will facilitate undertaking of requisite public health measures for the same,” the ministry said.

VK Paul, head of the national taskforce on COVID-19, met with Mansukh Mandaviya, Union health minister December 21. He later advised people to wear masks and increase booster uptake. No guidelines have been changed for international travel as yet.

China’s US Embassy spokesman Liu Pengyu told Bloomberg that China “continues to strengthen the genome monitoring of globally circulating, imported and locally circulating Omicron variants,” as well as the “timely assessment of emerging variants to provide a scientific basis for the continuous optimization of prevention and control policies.”

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