Low neutralization of SARS-CoV-2 Omicron BA.5.2.48, BF.7.14, XBB.1 subvariants by homologous or heterologous booster.

The recently mutated severe acute respiratory syndrome coronavirus 2 variant Omicron has very high infectivity and a strong ability to evolve and evade immunity. We collected six sets of sera from uninfected individuals and individuals recovering from breakthrough infections who completed homologous or heterologous booster immunization and assessed their susceptibility against the BA.5.2.48, BF.7.14, XBB.1.5, XBB.1.5.4, and XBB.1.16 subvariants. The results demonstrated that the Omicron variants possess an exceptional potential to evade the immune barriers strengthened by vaccine administration and natural infections in the population, particularly XBB.1.16, and showed that heterologous boosters exhibit higher vaccine efficacy compared with homologous boosters.