In July, Chinese drugmaker Sinovac Biotech began Phase 3 trials for its COVID-19 vaccine, collaborating with the Brazilian Butantan Institute located in Sao Paulo. However, the Phase 3 trials have been halted due to a serious adverse event involving a volunteer recipient, according to Brazilian media. The trials represent the most important testing stage before the vaccine’s approval and administration to the public.
The pause in testing comes amid Pfizer’s announcement that their vaccine boasts 90% effectiveness and no medical concerns were raised in the Phase 3 testing. According to the Brazilian National Health Surveillance Agency, an incident reported on October 29 led to the trial’s pause. Neither Chinese nor Brazilian authorities have offered specific information on the event, such as where it took place, due to privacy concerns. Sinovac claimed it was confident in the safety of the vaccine without offering an explanation for the suspension.
Read More: Brazil suspends trials of China’s Sinovac coronavirus vaccine, citing ‘serious adverse event’
