Sinovac COVID-19 Vaccine Trial Halted In Brazil Over Adverse Event

Brazilian health regulator has decided to halt clinical trials of a frontrunning Chinese vaccine following a “severe adverse event” observed in a participant, Bloomberg reported Monday. CoronaVac, a vaccine candidate developed through joint efforts by Chinese biopharma company Sinovac Biotech Ltd and Brazilian biologic research center Instituto Butantan, was in the final stages of testing.

What Happened: Reportedly, CoronaVac trials exhibited risks of immediate death, long term incapacitation, and hospitalization. The Brazilian authorities haven't yet released specifics about the health hazards or details on the adverse event.

Instituto Butantan is reviewing the trial results and is expected to share more information in a press conference on Tuesday.

Bloomberg noted that the Chinese Ministry of Science and Technology administered 60,000 participants with the vaccine last month but did not report any ill-effects of the drug.

Why Does It Matter: The CoronaVac vaccine trials in Brazil are already marred in a political conflict. Governor João Doria is in favor of a mandatory immunization and has been engaged in face off’s with President Jair Bolsanoro, a staunch critic of China, as reported by Bloomberg.

Earlier today, Reuters also reported that a facility was being set up in Sao Paulo to produce 100 million CoronaVac doses annually.

Vaccine trials from other pharma companies have also suffered setbacks. AZD1222, a vaccine being developed by AstraZeneca Plc AZN and Oxford University was temporarily paused after reports that a volunteer died in the U.K. A similar incident with AstraZeneca's drug was reported in October.

Pfizer Inc. PFE and BioNTech SE BNTX reported 90% efficacy for their COVID-19 vaccine candidate in interim results for late-stage clinical trials on Monday.