Brazil halts trials of Covid-19 vaccine

RIO DE JANEIRO (AFP) – Brazil’s health regulator said it had suspended clinical trials of a Chinese-developed COVID-19 vaccine after an “adverse incident” involving a volunteer recipient, a blow for one of the most advanced vaccine candidates.

The setback for CoronaVac, developed by China’s Sinovac Biotech, came on Monday as United States (US) pharmaceutical giant Pfizer said its own vaccine candidate had shown 90 per cent effectiveness – sending global markets soaring and raising hopes of an end to the pandemic.

Sinovac Biotech yesterday stood by its creation, saying, “We are confident in the safety of the vaccine.”

The Brazilian regulator Anvisa said it had “ruled to interrupt the clinical study of the CoronaVac vaccine after a serious adverse incident” involving a volunteer recipient on October 29.

It said it could not give details on what happened because of privacy regulations, but that such incidents included death, potentially fatal side effects, serious disability, hospitalisation, birth defects and other “clinically significant events”.

Sinovac, however, said the incident was “not related to the vaccine”, adding it will “continue to communicate with Brazil on this matter”. The Brazil public health centre, the Butantan Institute, said it was “surprised” by Anvisa’s decision.

A box of an experimental COVID-19 vaccine being tested in partnership with China’s pharmaceutical company Sinovac. PHOTO: AP