Brazil health regulator suspends Chinese-made vaccine trials

New Delhi (NVI): Brazil has suspended clinical trials of China’s CoronaVac vaccine, long expected to be one of the first to be approved in the country, following a severe adverse event involving a volunteer recipient, health regulator Anvisa said.

The regulator, Anvisa, said in a statement that it had “ruled to interrupt the clinical trial of the CoronaVac vaccine after a serious adverse incident” 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, hospitalization, birth defects and other “clinically significant events.”

The potential vaccine is being developed by Chinese biopharmaceutical firm Sinovac and in Brazil would be mostly produced by Sao Paulo’s state-run Butantan Institute.

Anvisa said in its statement that the event prompting the trial’s suspension occurred Oct. 29, without saying what transpired.

With the interruption of the study, no new volunteer can be vaccinated, the statement read.

Temporary halts of drug and vaccine testing are relatively common. In research involving thousands of participants, some are likely to fall ill. Pausing a study allows researchers to investigate whether an illness is a side effect or a coincidence.

Reportedly, CoronaVac is being tested in seven Brazilian states, plus the federal district where the capital Brasilia lies.

Last month, two drugmakers resumed testing of their prospective coronavirus vaccines in the United States after they were halted earlier.