An initial trial had given an effectiveness of 78%. New data reveals patients affected in a "very mild" way. Western-made drugs in circulation are more than 90% successful. Provisional trials in Turkey and Indonesia have yielded different results. Doubts about Chinese standards of approval.
Beijing (AsiaNews / Agencies) - Chinese Sinovac's coronavirus vaccine is only 50.4% effective, much less than the 78% previously announced, Brazilian researchers announced yesterday at the end of clinical tests. According to the World Health Organization parameters, a vaccine must be more than 50% effective in order to be distributed.
CoronoVac is an “inactivated” vaccine, obtained from killed microorganisms. According to Brazilian studies, its effectiveness is much lower than that of other drugs in circulation, such as the one manufactured by Moderna (94%) and Pfizer-BioNTech (95%). The new data was revealed after the Brazilian Butantan institute included information on trials carried out on patients suffering from "very mild" Covid-19.
Brazilian President Jair Bolsonaro has repeatedly expressed doubts about the origin of the drug produced by Sinovac. CoronoVac development project managers in Brazil said the country now has “a good vaccine. Not the best in the world and not the ideal one ". Beijing has already sent 10.7 million doses to Brasilia; another 40 million are awaiting shipment.
Brazilian authorities have yet to approve a second vaccine, one developed by Oxford University and AstraZeneca. With 200,000 deaths, the South American giant is one of the states most affected by the pandemic.
Other countries such as Indonesia, Turkey and Singapore have ordered doses of CoronoVac. The Turkish trials recorded a success rate of 91.25%; the Indonesian ones of 65.3: however, these are provisional results.
Many experts have criticized the process by which China approved its own vaccines as less transparent than those adopted in the West. Strong concern was expressed above all for the launch of the vaccination campaign before completing trials, including the large scale phase 3 trials.