Beijing/Sao Paulo. An experimental coronavirus vaccine developed by China’s Sinovac Biotech appeared to be safe in a late-stage clinical trial in Brazil, preliminary results showed on Monday.
São Paulo’s Butantan Institute, one of Brazil’s leading biomedical research centers, which is carrying out the Phase 3 tests, said the two-dose vaccine, called CoronaVac, proved to be safe in a trial so far involving 9,000 volunteers.
But Butantan director Dimas Covas said data on how effective the vaccine is will not be released until the trial is completed on all of the 13,000 volunteers.
“The first results of the clinical study conducted in Brazil prove that among all the vaccines tested in the country, CoronaVac is the safest, the one with the best and most promising rates,” São Paulo Governor João Doria told reporters.
The result is only preliminary and researchers will keep monitoring the participants in the on-going trial, Covas said. It’s the first set of results of Sinovac’s Phase 3 global trials, which are also being conducted in Turkey and Indonesia.
Covas said there were no severe adverse reactions to the vaccine, with 20% of the volunteers reporting mild pain from the injection while 15% reported headaches after the first dose, dropping to 10% for the second. Less than 5% reported nausea or tiredness, and even less had muscle aches, he said.
São Paulo state health secretary Jean Gorinchteyn said the vaccine appeared to produce protective anti-bodies. The state hopes to obtain regulatory approval for CoronaVac by the end of the year to start inoculating its population early in 2021, in what could the first vaccination programs in the Americas.
São Paulo signed a deal with Sinovac to buy 60 million doses by the end of February.
Sinovac wanted Brazil as a testing ground because it has been one of the global hotbeds of the virus, although cases are 43% off their peak of nearly 70,000 new cases a day in late July.
Brazil has reported more than 5.2 million COVID-19 cases since the pandemic began, the world’s third most-affected country after the United States and India. -Reuters