New Delhi (NVI): Coronavirus vaccine ‘CoronaVac’ developed by China’s Sinovac has been found to be 50.4 per cent effective in Brazilian clinical trials.
It shows the vaccine is significantly less effective than previous data suggested – barely over the 50 per cent needed for regulatory approval.
Notably, the Chinese vaccine is one of two that the Brazilian government has lined up.
Sinovac, a Beijing-based biopharmaceutical company, has developed CoronaVac, an inactivated vaccine.
It works by using killed viral particles to expose the body’s immune system to the virus without risking a serious disease response.
Several countries, including Indonesia, Turkey and Singapore, have placed orders for the vaccine.
Last week researchers at the Butantan Institute, which has been conducting the trials in Brazil, announced that the vaccine had a 78 per cent efficacy against “mild-to-severe” Covid-19 cases.
But on Tuesday they revealed that calculations for this figure did not include data from a group of “very mild infections” among those who received the vaccine that did not require clinical assistance.
With the inclusion of this data, the efficacy rate is now 50.4 per cent, said researchers.
However, the trial, which was used on 12,500 volunteers, did not produce any adverse effects or significant allergic reactions.