Abstract
To cope with the decline in COVID-19 vaccine-induced immunity caused by emerging SARS-CoV-2 variants, a heterologous immunization regimen using chimpanzee adenovirus vectored vaccine expressing SARS-CoV-2 spike (ChAd-S) and an inactivated vaccine (IV) was tested in mice and non-human primates (NHPs). Heterologous regimen successfully enhanced or at least maintained antibody and T cell responses and effectively protected against SARS-CoV-2 variants in mice and NHPs. An additional heterologous booster in mice further improved and prolonged the spike-specific antibody response and conferred effective neutralizing activity against the Omicron variant. Interestingly, priming with ChAd-S and boosting with IV reduced the lung injury risk caused by T cell over activation in NHPs compared to homologous ChAd-S regimen, meanwhile maintained the flexibility of antibody regulation system to react to virus invasion by upregulating or preserving antibody levels. This study demonstrated the satisfactory compatibility of ChAd-S and IV in prime-boost vaccination in animal models.
Keywords: COVID-19 vaccine; SARS-CoV-2 variants; animal model; heterologous immunization; protective effectiveness.
【저자키워드】 COVID-19 vaccine, animal model, SARS-CoV-2 variants, heterologous immunization, protective effectiveness., 【초록키워드】 COVID-19, SARS-CoV-2, vaccination, antibody, variant, SARS-CoV-2 variant, risk, animal models, Lung injury, omicron, virus, immunization, Neutralizing activity, T cell, Inactivated vaccine, mice, NHPs, Effectiveness, non-human primate, homologous, T cell response, Heterologous, booster, Protective, SARS-CoV-2 spike, Vaccine-induced immunity, Invasion, regimen, Activation, Regulation, priming, spike-specific antibody response, NHP, effective, caused, reduced, demonstrated, expressing, upregulating, adenovirus vectored vaccine, was tested, 【제목키워드】 SARS-CoV-2 variant, Adenovirus, Inactivated vaccine, mice, macaque, PROTECT,