BEIJING (REUTERS, NYTIMES) - An affiliate of China's state-owned drugmaker Sinopharm on Wednesday (Dec 30) said its Covid-19 vaccine showed 79.34 per cent efficacy and it has requested regulatory approval of the shot, moving it a step closer to becoming China's first approved vaccine for general public use.
The efficacy rate, based on an interim analysis of Phase 3 clinical trials, is lower than the 86 per cent rate for the same vaccine announced by the United Arab Emirates on Dec 9, based on preliminary data from trials there. A spokesman said detailed results would be released later.
There have been fragmentary releases of efficacy data for Chinese vaccine makers' Covid-19 candidates, which are being considered by many developing countries for mass inoculation campaigns. Health experts warn that piecemeal data without sufficient detail could undermine confidence in the vaccines.
Turkish researchers last week said interim results from a Covid-19 vaccine developed by China's Sinovac Biotech showed 91.25 per cent efficacy, but a confusing readout the same day from Brazil said the vaccine's efficacy was between 50 per cent and 90 per cent.
While the efficacy of the China-developed shots trails behind the more than 90 per cent success rate of rival vaccines from Pfizer-BioNTech and Moderna, it points to progress China has made in the global race to develop successful Covid-19 vaccines.
China, whose President Xi Jinping has pledged to make its vaccines a global public good, has won several large supply deals with countries including Indonesia and Brazil - the most populous countries in South-east Asia and Latin America respectively.
But none of the Chinese drugmakers has yet to release detailed efficacy data.
Public health professor Benjamin Cowling of the University of Hong Kong said: "I think it's very positive news. The results for other Covid-19 vaccines... were also released initially in very short press releases, and within a few weeks more details were provided."
Experts warn, however, that it is still early to conclude how successful the Sinopharm vaccine is.
"Data can only be interpreted when key details, such as the study design, number of participants, period of observation and number of cases, are described," said immunology professor Ooi Eng Eong from the National University of Singapore.
The Sinopharm vaccine has been used in China's emergency use programme to vaccinate hundreds of thousands of people since July.
Its developer Beijing Biological Products Institute, a unit of Sinopharm subsidiary China National Biotec Group (CNBG), said that it had applied to the National Medical Products Administration for conditional approval of the vaccine. CNBG has another vaccine in late-stage trials and both have been approved for emergency use in China though studies have not been completed.
Local governments across the country have embarked on an ambitious campaign to inoculate 50 million people by mid-February.
Rather than providing concrete late-stage trial data to show the efficacy of its vaccines, Chinese officials have issued broad statements assuring the public that they are safe and effective. By contrast, the United States and Britain started inoculations only after reviewing and approving such trial data.
Dr Tao Lina, a vaccine expert and a former immunologist at Shanghai Centre for Disease Control and Prevention, said he knew of several healthcare workers who declined the shots.
"In the minds of doctors, they feel that any drug that has not passed Phase 3 trials is unreliable."
Dr Tao, who received a Sinopharm vaccine on Monday, said he felt confident about the vaccines but that companies could do better in their messaging.
"If you say that it's safe, then you should show all kinds of evidence to show that it's safe," he said.
