Following the "unrelated" death of a trial volunteer, the late-stage trial of the experimental COVID-19 vaccine developed by China's Sinovac Biotech was suspended by the health regulator of Brazil.
On Monday, Anvisa, a national health surveillance agency, announced that amid the trials on October 29, a "severely adverse" event took place. However, it was not elaborated further.
The agency also stated that it has decided to suspend the ongoing study to evaluate available data that has already been observed and assess the benefits and risks of continuing the experiment.
In a statement by Dimas Covas, director of the Sao Paulo research center that partnered with Sinovac, Butantan Institute, he elaborated that the "severe adverse event" was the death of one of the volunteers. However, he questioned the health regulator's decision to halt the trials.
According to Yahoo! News, Cobas stated that the Anvisa order was strange since the death was completely unrelated to the trials. He noted that since there are at least 10,000 volunteers at the moment, a person can die of a traffic accident, but it should never be a reason to disrupt a clinical trial.
He also called on Anvisa to clarify their reason for the suspension.
Moreover, Sinovac has expressed confidence in the safety of its vaccine in a statement it released on Tuesday. The biotech company also said that it would be getting in touch with the Brazillian authorities regarding the matter.
Sinovac further added that it would continue to carry out the clinical trials in Brazil while complying with the Good Clinical Practice Requirements.
Meanwhile, in Indonesia and Turkey, where the experimental vaccine is also being tested, no clinical trials have been suspended.
In the past few months, it was not uncommon for the vaccine trials to be suspended. Back in September, the clinical trials for the experimental COVID-19 vaccine that was being developed by pharmaceutical giant AstraZeneca alongside Oxford University were also halted for a safety review. This happened after a participant in the trial suffered problems with his spinal cord, Reuters reported.
AstraZeneca's trials have already resumed just last month in South Africa, Britain, Brazil, Japan, and the U.S.
In addition, Johnson & Johnson also halted its trials last month after a participant suffered from an unexplained illness. However, the trials were immediately resumed after several days.
The decision of Anvisa to suspend the trials comes after Joao Doria, Governor of Sao Paulo, announced the groundbreaking of CorornaVac, a factory where the vaccine will be mass-produced. The operation of CoronaVac is expected to start as soon as approvals for the vaccine are granted.
Beijing-based company Sinovac Biotech's vaccine, has already been approved for the third phase of trials back in July. In September, the number of volunteers for the trials have gone up from 9,000 to 13,000, The Financial Times reported.
Just last month, Brazilian President Jair Bolsonaro stated that his government would not purchase Sinovac's vaccine since it came from China. He suggested that the country lacked credibility in developing a cure for the virus since it was where it all started.
Related article: Pfizer's COVID-19 Vaccine Candidate is 90% Effective, Experts Say