Researchers in Hong Kong have urged people to get a third dose of Covid-19 vaccine as soon as possible after a study showed insufficient antibodies were generated by the Sinovac and BioNTech products to fend off Omicron.

Tuesday's release of the results of a study by scientists in the microbiology department of the University of Hong Kong was the first published preliminary data on the impact of Sinovac's vaccine against the Omicron variant of coronavirus.