Chinese jabs' low efficacy casts doubt over global inoculation drive

BEIJING • Concern is mounting that China's Covid-19 vaccines are less effective at quelling the disease, raising questions about nations from Brazil to Hungary that are depending on the shots and the country's own mammoth inoculation drive.

While vaccines developed by Pfizer and Moderna and even Russia's Sputnik shot have delivered protection rates of more than 90 per cent, Chinese candidates have generally reported much lower efficacy results.

Research released on Sunday showed the rate for Sinovac Biotech's vaccine CoronaVac - deployed in Indonesia and Brazil - was just above 50 per cent, barely meeting the minimum protection required for Covid-19 vaccines by leading global drug regulators.

The other Chinese shots have reported efficacy rates of between 66 per cent and 79 per cent.

Anxiety over that disparity spilled into the open at the weekend when Dr Gao Fu, head of the Chinese Centre for Disease Control and Prevention, said at a forum that something needs to be done to address the low protection rate of the Chinese vaccines, according to local news outlet the Paper.

The rare admission by a senior official appeared to go viral on social media before China's censors swung into action, with posts and media reports about Dr Gao's comments quickly edited or taken down.

Dr Gao then backtracked, telling the state-backed Global Times newspaper on Sunday that his remarks were misinterpreted, and were meant only to suggest ways to improve the efficacy of vaccines.

He suggested that following up inoculations with additional booster shots and mixing different types of vaccines could help tackle the effectiveness issue, according to the Global Times.

The concerns put a question mark over a vast swathe of the global vaccine roll-out, particularly in the developing world, with richer countries' domination of supplies of the highly effective mRNA vaccines seeing countries like Turkey and Indonesia turn instead to China's shots.

China has urged the local authorities to halt compulsory coronavirus vaccinations as the central government tries to balance the urgency of its inoculation efforts and possible backlash from a hesitant population. The directive appears to be aimed at curbing the heavy-handed tactics of some local authorities to ramp up vaccinations after the government set a target of vaccinating 40 per cent of the population, or some 560 million people, by the end of June.

While China is working on more effective vaccines, including shots that deploy mRNA technology, it should continue to roll out those that have been approved for now, said head of epidemiology and biostatistics Benjamin Cowling of the University of Hong Kong.

"They can provide a high level of protection, particularly against severe Covid," he said.

BLOOMBERG