Brazil's health regulator has said it had suspended clinical trials of a Chinese-developed Covid-19 vaccine after an "adverse incident" involving a volunteer recipient.
The setback for CoronaVac, developed by Chinese pharmaceutical firm Sinovac Biotech, comes as US pharmaceutical giant Pfizer said yesterday its own vaccine candidate had shown 90% effectiveness, sending global markets soaring and raising hopes of an end to the pandemic.
The Brazilian regulator, Anvisa, said in a statement it had "ruled to interrupt the clinical study of the CoronaVac vaccine after a serious adverse incident" on 29 October.
It said it could not give details on what happened because of privacy regulations, but that such incidents included death, potentially