China study warns of 'colossal' COVID-19 outbreak

Warning about a "colossal" COVID-19 outbreak, a new study by the Chinese mathematicians has advised against dropping the country's zero-tolerance policies by lifting travel curbs.

China could not afford to lift travel restrictions without more efficient vaccinations or specific treatments, said Peking University mathematicians, in the report published in China CDC Weekly by the Chinese Centre for Disease Control and Prevention.

Making use of data provided by the United States, Britain, Spain, France and Israel, the researchers assessed the possible outcomes if China adopted the same pandemic control strategies.

"The estimates revealed the real possibility of a colossal outbreak which would almost certainly induce an unaffordable burden to the medical system. Our findings have raised a clear warning that, for the time being, we are not ready to embrace "open-up" strategies resting solely on the hypothesis of herd immunity induced by vaccination advocated by certain western countries," the study said.

More efficient vaccinations or more specific treatment, preferably the combination of both, are needed before entry-exit quarantine measures and other COVID-19 response strategies in China can be safely lifted, it added.

The study refuted the arguments that a higher infection size is more tolerable provided that severe cases of COVID-19 have been substantially reduced under the large-scale vaccination campaign.

"While vaccination has been proved to significantly reduce the development of severe symptoms after infection from the original and mutated strain of the virus, the emergence of new mutated strains would potentially disrupt such protection," the study said.

Amid rising global vaccination rates in several parts of the world, China is doubling down on its zero-tolerance policy.

Since the outbreak of the COVID-19 pandemic in Wuhan last year, China has taken the approach of strict lockdowns, multiple rounds of mass testing, and centralized quarantine. Even after purportedly vaccinating 77 per cent of its 1.4 billion people and giving booster shots, Beijing has continued with the same policy despite major consequences.