The Chinese Sinovac vaccine has been shown to be 78% effective against Covid-19 in Brazilian late-stage trials and offers overall protection against severe cases of the disease, creating hope that it can immunize many of the developing countries.
The Butantan Institute in Brazil, the São Paulo-based research center that tested CoronaVac in phase 3 trials, said Thursday that none of the volunteers who took the vaccine developed serious cases of Covid-19. More than 12,000 health workers took part in Phase 3 trials in Brazil, the first country to complete tests of Sinovac’s vaccine.
“This is an excellent result,” said Luiz Carlos Dias, part of a Covid-19 task force of researchers at the University of Campinas in the state of São Paulo. “If it can prevent serious cases, hospitalizations and deaths, it can get us out of this pandemic.”
The vaccination of CoronaVac is less effective than that used by Moderna Inc. and jointly by Pfizer Inc. and BioNTech SE, which have been shown to have efficiencies of 94.5% and 95% in the test, respectively. But CoronaVac can be kept in a standard refrigerator between about 36 and 46 degrees Fahrenheit, making transportation and storage in less developed countries easier and cheaper, infectious disease specialists said.
Prashant Yadav, a global health specialist at the think tank Center for Global Development in Washington, said 78% is a high rate for many developing countries to use the vaccine and may be good enough to consider the World Health Organization to include CoronaVac in global distribution system.