Modeling the Prediction on the Efficacy of a Homologous Third Dose of CoronaVac Against SARS-CoV-2 Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5-China, 2020-2021
What is already known about this topic? Previous studies have reported vaccine efficacy or effectiveness against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariants for several vaccine platforms. However, there are currently few data on estimates of inactivated platform coronavirus disease 2019 (COVID-19) vaccines, especially against the globally dominant subvariant — Omicron BA.5. What is added by this report? The study predicts vaccine efficacy against four Omicron subvariants — Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5 — after vaccination with a homologous third dose of CoronaVac across clinical endpoints and age groups. What are the implications for public health practice? The results suggest that CoronaVac-elicited immunity may not provide adequate protection against Omicron subvariants after the homologous third dose, and a heterologous booster and Omicron-specific vaccination may be alternative strategies.
