China has yet to detect any dangerous Covid mutations in the six weeks since the virus was unleashed on the country’s 1.4 billion people after the abandonment of the rigid curbs that held the pathogen largely at bay.

That’s bolstering hope that a new variant after omicron – one that could set the world back in its attempts to move past the pandemic – is less likely to emerge, even as China contends with an explosive wave.

It’s a stark contrast to more than a year ago, the last time when the World Health Organization christened a new strain. Back then, concerns were high that the Greek alphabet might be exhausted soon. There’s now little room left in some of the virus’ key architecture for any major mutations, according to one of China’s top scientific advisers.

Most of the changes that gave rise to new variants occurred in the spike protein, the portion of the virus used to latch onto healthy cells that works similar to a key fitting into a lock. The raft of modifications in an important amino acid on the spike protein means it’s close to saturation, Zeng Guang, the former chief scientist at the Chinese Center for Disease Control and Prevention, said at a seminar on Thursday, local media Caixin reported.

Future Variants

While it’s still possible that omicron could evolve further or undergo changes such as fusing with other coronaviruses, Zeng said he has “cautious optimism” about the risk of future variants.

China has a clear interest in staying officially new variant-free after years of geopolitical acrimony over how the virus originated. Other scientists aren’t as sanguine, warning that even small changes could be devastating and that the emergence of mutations have always been random, defying predictions.

“The next variant will come in due course, whether it’s from China or elsewhere, and it may not be from the omicron family,” said Eric Topol, director of the Scripps Research Translational Institute in La Jolla, California.

Fresh global concerns over novel variants have taken hold in recent weeks, with countries imposing restrictions on Chinese travelers as the virus swamped the world’s most populous country with breathtaking speed.

The absence of comprehensive information from China makes it “understandable” that other nations are taking steps they believe will protect their populations, WHO Director-General Tedros Adhanom Ghebreyesus said two weeks ago, calling for more details so the health agency can undertake a comprehensive risk analysis.

The risk that the pathogen mutates further, diverging from the highly-infectious but less virulent forms of omicron that have dominated the pandemic since it emerged in November 2021, is what researchers fear most. If that occurs, and a new variant that is expected to carry the Greek letter Pi emerges, all bets are off.

“With omicron, our Covid wards are still mostly empty,” said Alex Sigal, a virologist at the Africa Health Research Institute in Durban. “At least part of that has to do with the variant, and not only a buildup of immunity. With a new variant, you don’t know what will happen.”

‘Unscientific and Ungrounded’

To be sure, China, while largely abandoning testing and tracking of cases, has ramped up genetic sequencing efforts. Nearly 1,000 submissions from more than a dozen provinces have been sent to the GISAID consortium that’s tracking variants since officials started rolling back the Covid Zero approach in November.

All the strains spreading in China closely resemble the variants previously found elsewhere in the world, according to GISAID data. The findings are consistent with the results of genetic sequencing done on infected airline passengers from China arriving in other countries, Wu Xi, an official with China’s Ministry of Foreign Affairs, told reporters at a briefing in Beijing held by the National Health Commission on Friday.

“There is no new variant nor significant mutations,” she said. “Therefore, some countries’ accusations and speculation against us is absolutely unreasonable, unscientific and ungrounded.”

Still, with the former chief scientist Zeng warning that China’s wave will last another two to three months, there’s some way to go before the world is out of the woods.

(Bloomberg)

A vial containing swab samples at a Covid-19 testing site in Shanghai. (Bloomberg)

China finds no new Covid variants but mutation threat lingers