Chinese state-run pharmaceutical giant Sinopharm said its COVID-19 vaccine was nearly 80 percent effective in final-stage clinical trials.
The vaccine, produced by its subsidiary the Beijing Institute of Biological Products, was found to be 79.34 percent effective after two shots, the company said in an online statement on Wednesday.
This made Sinopharm the first Chinese vaccine maker to publish results from a large clinical trial of a COVID-19 vaccine. The company said it has applied for regulatory approval in China.
But Sinopharm has not provided details such as the scope of the trial and the demographic of the participants, data that experts say is needed to determine whether the shot is suitable for mass vaccination campaigns.
“For example, is the sample size 100 people, or 1,000 or 10,000?” said Jin Dong-yan, a virologist at the University of Hong Kong. “If they don’t release any data, we could only put a question mark there.”
He said that statistics shared by Chinese vaccine makers are so far not comparable to what has been released by Pfizer-BioNTech and Moderna.
Chinese drugmakers have been racing against their Western peers in producing viable vaccines for the new coronavirus. But they have mostly played catch-up in publishing clinical trial data, in part because China has few cases of the coronavirus and must conduct these trials overseas.
So far, the vaccine developed by Pfizer-BioNTech has received approval for use in the largest number of countries, including the United States, United Kingdom and the European Union. Moderna’s vaccine has been approved in the U.S. and Canada.
Compared to vaccines from Pfizer-BioNTech and Moderna, the Sinopharm shot does not need to be kept at ultra-low temperatures, making it a particularly attractive option for poorer countries that lack capacity for extreme cold storage.
On Wednesday, the U.K. became the first country to authorize a vaccine developed by the University of Oxford and AstraZeneca. The vaccine was found to be 70 percent effective overall. Like the Sinopharm shot, the Oxford-AstraZeneca vaccine can be stored at normal refrigerator temperatures.
Although the Sinopharm vaccine’s efficacy was lower than those of Moderna’s (94.1 percent) and Pfizer’s (95 percent), the rate is well above the 50 percent threshold set by international scientists for COVID vaccines to be viable for mass use.
Sinopharm’s two inactivated vaccines have already been adopted in China for emergency use. A company executive said in November that nearly one million people worldwide had been injected, with no report of side effects.
The United Arab Emirates approved the Sinopharm vaccine earlier this month, citing an interim efficacy rate of 86 percent. Bahrain has also approved a Sinopharm vaccine. The countries did not publish detailed data from their trials.
Although Chinese pharmaceutical companies have pledged to supply tens of millions of shots to developing nations, their delay in presenting detailed clinical data has raised questions of transparency and could hurt confidence in the products.
Jin, of the University of Hong Kong, said while state-run companies like Sinopharm have largely dealt with domestic regulators in the past, they now need to appeal to consumers, scientists and governments globally.
“They have not been under such type of scrutiny in their lifetime,” he said. “In that case, they don’t have good advisers in doing these.“
Private drugmaker Sinovac, another frontrunner in the vaccine race in China, has tested its inactivated vaccine in Brazil, Indonesia and Turkey. Brazilian researchers said the vaccine is more than 50 percent effective, but the company has not published full clinical data.
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