SÃO PAULO, Brazil (CU)_ CoronaVac, the COVID-19 vaccines developed by China, has been found to be 50.4 per cent effective in Brazilian clinical trials, the researchers say.
Brazil has been one of the countries worst affected by COVID-19, and the Chinese vaccine is one of the two vaccines lined up by the Brazilian government.
CoronaVac, developed by a Beijing-based biopharmaceutical company Sinovac, uses killed viral particles to expose the body’s immune system to the virus, and apart from Brazil, several other countries, including Singapore, Turkey and Indonesia have placed orders for the vaccine.
The Butantan Institute, a world-renowned research institute located in São Paulo, has been conducting the trials in Brazil.
Last week, the Institute announced that CoronaVac has a 78 per cent efficacy against “mild-to-severe” COVID-19 cases, although later it was revealed that the calculations for this figure did not include data from a group of “very mild infections” among those who received the vaccine. Subsequently, the researchers said that with the inclusion of this data, the vaccine has an efficacy rate of 50.4 per cent.
However, the researchers stressed that the vaccine is still 78 per cent effective in preventing mild infections and 100 per cent effective against serious cases.
The CoronaVac trials have produced different results across various countries. For instance, Turkey said last week that CoronaVac is 91.25 per cent effective against COVID-19, while Indonesian researchers say its efficacy rate is 65.3 per cent.
Nevertheless, there has been widespread criticism that Chinese vaccine trials do not maintain the same level of scrutiny and transparency as those developed by Western countries.
Meanwhile, the Oxford University and pharmaceutical firm AstraZeneca have also requested for emergency use authorisation for their COVID-19 vaccine in Brazil.
The South American nation is currently dealing with a major spike in infections, as Brazil has reported the third highest number of COVID-19 cases in the world, at over 8.1 million, just behind the US and India.
