Safety and superior immunogenicity of heterologous boosting with an RBD-based SARS-CoV-2 mRNA vaccine in Chinese adults

Abstract

Homologous and heterologous booster with COVID-19 mRNA vaccines represent the most effective strategy to prevent the ongoing Omicron pandemic. The additional protection from these prototype SARS-CoV-2 S-targeting vaccine was attributed to the increased RBD-specific memory B cells with expanded potency and breadth. Herein, we show the safety and immunogenicity of heterologous boosting with the RBD-targeting mRNA vaccine AWcorna (also term ARCoV) in Chinese adults who have received two doses inactivated vaccine. The superiority over inactivated vaccine in neutralization antibodies, as well as the safety profile, support the use of AWcorna as heterologous booster in China.

Vaccination with S pan , an antigen guided by SARS-CoV-2 S protein evolution, protects against challenge with viral variants in mice

“…Recent studies revealed that the heterologous boost strategy could enhance the background neutralization ability induced by the prototype strain vaccine (47)(48)(49). However, this strategy was not fully effective against Omicron subvariant infection (50).…”

Challenges and developments in universal vaccine design against SARS-CoV-2 variants

“…In reverse, heterologous boosting with Ad26.COV2.S after BNT162b2 prime vaccination can also induce durable humoral and cellular immune responses 72 . An inactivated vaccine plus a recombinant adenovirus vectored vaccine or a recombinant protein subunit vaccine or a mRNA vaccine are additional heterologous vaccine regimens [73][74][75][76][77] . For example, initial vaccination with two doses of CoronaVac followed by heterologous boosting with the Ad5-nCoV induced significantly higher neutralizing antibody levels against the index virus and the Delta variant than did homologous boosting (5.9-fold and 6.7-fold, respectively) 73 .…”