PARIS, France (AFP) — An explosion of Covid-19 cases in China as the country lifts its zero-Covid measures could create a "potential breeding ground" for new variants to emerge, health experts warn.

China announced this week that incoming travelers would no longer have to quarantine from 8 January, the latest major reversal of strict restrictions that have kept the country largely closed off to the world since the start of the pandemic.

While the country's National Health Commission has stopped issuing daily case numbers, officials in several cities estimate that hundreds of thousands of people have been infected in recent weeks.
Hospitals and crematoriums have been overwhelmed across the country.

With the virus now able to circulate among nearly one-fifth of the world's population — almost all of whom lack immunity from previous infection and many of whom remain unvaccinated — other nations and experts fear China will become fertile ground for new variants.

Antoine Flahault, director of the Institute of Global Health at the University of Geneva, told AFP that each new infection increased the chance the virus would mutate.

"The fact that 1.4 billion people are suddenly exposed to SARS-CoV-2 obviously creates conditions prone to emerging variants," Flahault said, referring to the virus that causes the Covid-19 disease.

Bruno Lina, a virology professor at France's Lyon University, told the La Croix newspaper this week that China could become a "potential breeding ground for the virus."

Soumya Swaminathan, who served as the World Health Organization's chief scientist until November, said a large part of the Chinese population was vulnerable to infection in part because many elderly people had not been vaccinated or boosted.

Hundreds of thousands of people have been infected in recent weeks.

"We need to keep a close watch on any emerging concerning variants," she told the website of the Indian Express newspaper.

Countries test Chinese visitors

In response to the surging cases, the United States, Italy, Japan, India and Malaysia announced this week they would increase health measures for travelers from China.

The lack of transparent data from China — particularly about viral genomic sequencing — is making it "increasingly difficult for public health officials to ensure that they will be able to identify any potential new variants and take prompt measures to reduce the spread," US officials said Tuesday.

India and Japan have already said they will impose mandatory PCR testing on all passengers from China, a measure Flahault said could be a way around any delays in information from Beijing.

"If we succeed to sample and sequence all viruses identified from any travellers coming in from China, we will know almost as soon as new variants emerge and spread" in the country, he said.