Brazil's regulatory body authorizes restart of COVID-19 CoronaVac vaccine trials

Brazil's National Health Surveillance Agency (Anvisa) on Wednesday authorized the resumption of clinical trials of its COVID-19 vaccine CoronaVac, developed by Chinese biopharmaceutical producer Sinovac Biotech.

The move comes after Anvisa suspended phase three of the trials on Monday due to a "serious adverse event," believed to be the death of a volunteer.

According to the Civil Police, the death occured by suicide and was unrelated to the vaccine.

"After evaluating the new data presented by the sponsor (the Butantan Institute) following the suspension of the study, Anvisa understands that there are sufficient benefits to allow the vaccination to resume," Anvisa said in a statement, adding it had suspended the trials on the basis of the "precautionary principle."

The trials are being carried out on more than 10,000 volunteers in Brazil by Sao Paulo's state-run Butantan Institute, the country's main vaccine supplier and operator of the largest public immunization factory in Latin America.

"The aforementioned death is not related to the vaccine and therefore the study could be resumed," the Butantan Institute said.

"We are confident in the safety of the vaccine, (and) fully understand and appreciate Anvisa's strict supervision and timely resumption of clinical studies. We look forward to completing the following clinical research as soon as possible under the strict governance and monitoring by Anvisa, and finally control the pandemic through vaccination," Sinovac Biotech said in a statement.