“In doing so, they could engage in behaviour that has a higher risk…[and] unwittingly put other people at risk.
“The reason why vaccines go through phase 3 trials is to reduce the short and long-term risk to the individual,” he said. “Giving vaccine shots without this knowledge places individuals at significant personal risk.”
The Chinese government has provided sparse details on which vaccines are being given to people, and how many have been vaccinated, leading to concerns participation may be forced and not voluntary.
Last week, Papua New Guinea cancelled a flight from China filled with arriving passengers believed to have received a coronavirus vaccine over worries of the unknown health impact to the local population.
In general, “it’s better for a community if there’s more people vaccinated, so there’s less risk of an outbreak of COVID,” said Ben Cowling, division head of epidemiology and biostatistics at Hong Kong University’s School of Public Health.
“At the same time, just having some vaccinated people wouldn’t be enough to mean that social distancing could be relaxed.”
Governments are under increasing pressure to find a lasting solution for the pandemic that has killed more than 840,000 people.
For China, coming up with a successful vaccine would help to deflect anger at home and abroad over its pandemic cover-up, while delivering a blow to Donald Trump’s “warp-speed” plans for a vaccine. Competition is heating up as well with Russia.
The Chinese government “sees science and technology as tools of national greatness,” said Yangyang Cheng, a scientist at Cornell University.
Winning the vaccine race would underscore government propaganda about how “it’s really a hostile world out there, and we, as in the Chinese people, have to rely on ourselves”.
It would also give China a new tool for diplomacy and potentially bring more allies into the fold.
Beijing has already vowed “to give priority” to a number of South-east Asian nations – the Philippines, Cambodia, Laos, Myanmar, Thailand and Vietnam – if it develops a vaccine.
Whether the world will trust a Chinese vaccine remains to be seen.
If early inoculations in China end up failing, experts say that could impact global public confidence in the efficacy of coronavirus vaccines in general.
While drug regulators have the power to decide whether or not to approve a Chinese vaccine for use in their own countries, they could come under pressure to fast-track a successful candidate on the market, regardless of who developed the treatment.