(Reuters) – Brazil’s health regulator said yesterday it had suspended clinical trials for China’s Sinovac coronavirus vaccine, due to a “severe adverse effect” that took place on Oct. 29 but did not immediately provide further details.
Sao Paulo’s medical research institute Butantan, which is conducting the Sinovac trials in Brazil, said it “was surprised” by the decision and would hold a news conference today at 11 a.m. local time (1400 GMT).
The head of Butantan, Dimas Covas, speaking to local broadcaster TV Cultura, said the decision was related to a “death” but said he found the regulator announcement strange “because it’s a death unrelated to the vaccine.”
“As there are more than 10,000 volunteers at this moment, deaths can occur… It’s a death that has no relation with the vaccine and as such it is not the moment to interrupt the trials,” Covas said.
The health regulator, Anvisa, did not specify whether the incident took place in Brazil – where trials are being conducted – or in another country. It also did not say why news of the October event was being communicated only now.
Sinovac did not immediately respond to requests for comment.
No other country conducting trials of Sinovac’s experimental vaccine has announced a suspension. Late-stage trials are also being conducted in Indonesia and Turkey.
Sinovac’s vaccine is among the three experimental COVID-19 vaccines that China has been using to inoculate hundreds of thousands of people under an emergency use programme, and a Chinese health official said on Oct. 20 that serious side effects have not been observed in clinical trials.