Preliminary Trials Show Sinovac-BioNTech Mix Is Safe

A government advisor on Covid-19 vaccination says preliminary trial results show mixing the use of Sinovac and BioNTech vaccines is effective and safe.

Professor Ivan Hung told RTHK's Hong Kong Today programme that the incidence of side effects, when mixing the shots, was comparable to people who'd been fully-vaccinated with two shots of the same vaccine. But he said results were not yet available on the antibody levels of people who'd received mixed doses.

However, their study backed up international studies, which showed antibody levels of people who'd had a Sinovac jab were lower than those who had received BioNTech.

Professor Hung said the antibody levels following Sinovac were about 10 times lower than BioNTech. He said this meant people fully-vaccinated with Sinovac should probably have a third booster shot about six months after finishing their second dose.

Professor Hung also said that, given the spread of the Delta variant around the world, if that variant entered the community in Hong Kong, parents might consider getting a second vaccine shot for their children.

Last month, Hong Kong revised its vaccination advice for adolescents aged 12-17, following several cases of heart inflammation in youngsters, mostly after they'd received their second jab. Professor Hung says a second jab would be advisable to protect against the Delta variant but wasn't necessary right now, given the low number of cases in the city.