SARS-COV-2 surrogate virus neutralization antibody response
The breadth and magnitude of neutralizing antibody responses to various SARS-CoV-2 variants were investigated via an SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT) based on the RBD-ACE2 competitive binding assay. In all the groups, the better antibody responses were against wild-type strain, Alpha and Delta variants, and the worst were against Omicron variants. Ad5-nCoV-IH booster vaccination elicited most potent cross-reactivity neutralizing antibody responses in wild-type, Alpha, Beta, Delta, Omicron BA.1, BA.2 and BA.4/5 variants, followed with Ad5-nCoV-IM, ZF2001 and CoronaVac booster vaccination at day 28 and month 6 post-vaccination (SARS-CoV-2 sVNT neutralizing antibody responses. 