BEIJING -- China's vaccine diplomacy faces a setback as questions arise about the efficacy and safety of its coronavirus inoculations while the country speeds a large-scale rollout despite the candidates remaining in the clinical trial phase.
Beijing once led the global race to develop a COVID-19 vaccine, but U.S. and European pharmaceutical firms are close to bringing candidates to market.
On Nov. 17, British medical journal The Lancet featured a study about the efficacy of Sinovac Biotech's vaccine candidate based on initial clinical trials. It found that the Chinese company's candidate generated lower levels of protective antibodies than those present in recovered coronavirus patients. The efficacy was determined to be moderate.
In contrast, the candidates from U.S.-based Pfizer and Moderna were found to be more than 90% effective, while the offering from Britain's AstraZeneca had an overall efficacy rate of 70%. Both American pharma companies used cutting-edge technology to develop their products.
Sinovac used an inactivated virus that does not induce illness to develop its candidate, a tried-and-true method long employed for fighting pathogens such as influenza. The report of moderate success therefore caused ripples because more solid results were expected.
The team in The Lancet study confirmed the presence of antibodies and found no safety problems, sufficient evidence to continue with clinical trials. Sinovac senior director Meng Weining told an online conference on Nov. 20 that final-phase trials were proceeding smoothly.
"I guess maybe next month we'll have data available," he said.
Eleven vaccine candidates worldwide are in final clinical trials, four of them Chinese. China began vaccine development at a fevered pitch in January, mainly through Sinovac and state-owned giant Sinopharm Group.
Both companies have ramped up inoculations at home, even while remaining in the midst of final-stage trials.
People lined up to receive inoculations Thursday at a Sinopharm research lab in Beijing, a program that has been expanded before the end of clinical trials.
Nearly 1 million people have received inoculations, the company said Nov. 18, up from 350,000 in September. Inoculations of individuals such as employees of state-owned companies have nearly tripled over the past two months.
Several such employees reported being inoculated in September but that Sinopharm made no attempt to contact them.
This raises questions about the effort being made to check on the health of people receiving a vaccine under development. Normally such contact would occur right after inoculation, as well as six months to a year later.
"After close to 1 million inoculations, there has not been a single adverse reaction," Sinopharm Chairman Liu Jingzhen said in a statement Nov. 18.
The development of coronavirus vaccines is being followed intensely worldwide. European and U.S. pharma companies have been aggressively transparent in the process, disclosing clinical trial data and reporting side effects.
Pfizer applied for emergency approval from the U.S. Food and Drug Administration on Nov. 20, and inoculations are expected to begin as early as Dec. 11.
Sinopharm applied to China's national drug administration on Wednesday for permission to sell the vaccine candidate, the state-owned Xinhua News Agency reported. The details are unknown, but Sinopharm could start moving from emergency administration of the drug to preparation to general sales.
Three Chinese companies -- Sinovac, Sinopharm and CanSinoBio -- are conducting final clinical trials in at least 13 countries, including Indonesia and Brazil. Those countries will be first in line if the candidates are successful.
This priority vaccine supply arrangement is part of President Xi Jinping's goal to expand Chinese influence in the developing world. But the rapid development of entirely new vaccines is a risky endeavor, and it remains to be seen whether China can regain leadership in coronavirus vaccine development.