CS-2034 mRNA vaccine: a new option for COVID-19 infection?

Overall, the heterologous vaccination with CS-2034 vaccine was safe and very well tolerated, and most reported adverse events were mild and moderate, with only 2% of participants reporting severe adverse events. Several studies show that a heterologous immunisation strategy triggers a higher immune response than a homologous immunisation strategy, such as ChAdOx1-S/BNT162b2 versus homologous ChAdOx1-S, CoronaVac/BNT162b2 versus homologous CoronaVac, and BBIBP-CorV/BNT162b2 versus homologous BNT162b2.6,7 Similar to findings of these trials, heterologous CS-2034 boosting elicited a higher humoral response and cellular response than homologous BBIBP-CorV booster. [...]the current COVID-19 vaccines have diminished efficacy in protection against SARS-CoV-2 transmission and infection, despite proven effectiveness in reducing the risk of severe COVID-19 infection and related death.8 New COVID-19 vaccines administered via the intranasal route might overcome this hurdle by conferring better upper respiratory tract mucosal immunity against the SARS-CoV-2.9 As the majority of the population in China and many countries worldwide have received homologous immunisation with inactivated COVID-19 vaccines (CoronaVac or BBIBP-CorV), Wu and colleagues provide important evidence in this phase 2b study to support heterologous boosting with the CS-2034 mRNA vaccine as a new option against the circulating omicron variants.