China's Sinopharm publishes awaited COVID vaccine trial data; fails to cover vulnerable groups

Beijing [China], May 27 : The Chinese drug maker Sinopharm has finally published the interim results of a phase 3 trial of its COVID-19 vaccine, however, the results do not cover some of the most vulnerable groups.
After 200 millions of its doses have been administered worldwide, trial data shows a vaccine made by Sinopharm's Beijing subsidiary, which has been approved by the World Health Organisation for emergency use, could offer 78.1 per cent of protection against symptomatic COVID-19 but the rate dropped to 73.5 per cent after taking asymptomatic cases into account, reported South China Morning Post (SCMP).
Beijing' efforts have also been hampered by the refusal of its pharmaceutical companies to release data on the efficacy of their vaccines, which has drawn a sharp reaction from many experts.
Although some say that the data has finally answered scientists' calls for greater transparency, the results do not cover some of the most vulnerable groups.
Another vaccine by the company's Wuhan subsidiary, which is in the process of applying for WHO emergency use licensing and has been conditionally approved for general use in China, had 72.8 per cent efficacy against symptomatic cases and 64 per cent including asymptomatic ones.
The results were based on data collected from 40,411 participants in the United Arab Emirates (UAE) and Bahrain last year. Participants were mostly healthy from 18 to 59 years old.
A total of 142 symptomatic cases were recorded, 26 from the Wuhan vaccine group, 21 from the Beijing vaccine group, and 95 from the placebo group. Only two severe cases were identified in the placebo groups, which the researchers said did not provide enough data to make a conclusion, SCMP reported.
Immunologist Ashley St John said that the low number of severe cases could be down to the low number of elderly participants or those with comorbidities, but a higher number of severe cases may have generated more confidence.
"Certainly they don't have enough data on severe cases, and from a statistical standpoint we would need to see more cases to have a better idea how well this vaccine protects against severe disease... When you have values like two or three out of hundreds [for severe cases], they don't give you confidence that it's not just a random event," St John said.
Vaccinologist Nikolai Petrovsky also said that the numbers were not big enough to make a "statistical claim of difference".
The authors of the study said that the trial was mainly conducted in healthy, young men and there was insufficient power to test the efficacy among those with chronic diseases, women, older adults, those in other geographic populations, and those with previous SARS-CoV-2 infections, SCMP reported.
The WHO has recommended the vaccine for use on over-60s but said further data on that age group is needed.
China's export of millions of vaccine doses has come amid doubts over the efficacy of its vaccines and concerns by industry analysts about whether its production capacity will be able to keep up with an ever-expanding list of overseas customers.