Serum neutralising antibodies measured by live virus PRNT (A–C) or by sVNT (D–F) against ancestral SARS-CoV-2, omicron BA.1, and omicron BA.2, respectively, at baseline and 28 days after randomised third-dose CoronaVac or BNT162b2 vaccination
PRNT titres were evaluated with endpoint at 50% inhibition (PRNT