SAO PAULO : Brazil's health regulator Anvisa said on Monday China's health authorities are not transparent in their authorization of COVID-19 vaccines for emergency use, a statement that may further inflame political tension in the South American country.Brazilian President Jair Bolsonaro, a consistent critic of China, has repeatedly cast doubt on the CoronaVac vaccine being developed by China's Sinovac Biotech Ltd.Meanwhile, Sao Paulo Governor Joao Doria, a Bolsonaro enemy, said the state expected to start vaccinating its residents in January, though Brazil's most populous state will not be able to use CoronaVac until it is approved by Anvisa."Brazil is the international leader in the evaluation process for CoronaVac," Anvisa said in a.