Immunogenicity and efficacy of vaccine boosters against SARS-CoV-2 Omicron subvariant BA.5 in male Syrian hamsters.

Publication date: Jul 17, 2023

The SARS-CoV-2 Omicron subvariant BA. 5 rapidly spread worldwide and replaced BA. 1/BA. 2 in many countries, becoming globally dominant. BA. 5 has unique amino acid substitutions in the spike protein that both mediate immune escape from neutralizing antibodies produced by immunizations and increase ACE2 receptor binding affinity. In a comprehensive, long-term (up to 9 months post primary vaccination), experimental vaccination study using male Syrian hamsters, we evaluate neutralizing antibody responses and efficacy against BA. 5 challenge after primary vaccination with Ad26. COV2. S (Janssen) or BNT162b2 (Pfizer/BioNTech) followed by a homologous or heterologous booster with mRNA-1273 (Moderna) or NVX-CoV2373 (Novavax). Notably, one high or low dose of Ad26. COV2. S provides more durable immunity than two primary doses of BNT162b2, and the NVX-CoV2373 booster provides the strongest augmentation of immunity, reduction in BA. 5 viral replication, and disease. Our data demonstrate the immunogenicity and efficacy of different prime/boost vaccine regimens against BA. 5 infection in an immune-competent model and provide new insights regarding COVID-19 vaccine strategies.

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Concepts Keywords
9months Ad26
Durable Ba
Hamsters Cov
Vaccines Efficacy


Type Source Name
disease VO vaccine
disease VO primary vaccination
disease VO vaccination
disease VO Ad26.COV2.S
disease VO NVX-CoV2373
disease VO dose
pathway KEGG Viral replication
disease MESH infection
disease VO COVID-19 vaccine
disease MESH COVID 19
disease IDO replication
disease VO USA
disease MESH Emerging Infectious Diseases
disease MESH reinfections
disease MESH AURA
disease VO immunized
disease VO vaccinated
disease VO injection
disease VO immunization
disease IDO assay
disease VO time

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