The ChAdOx1 vectored vaccine, AZD2816, induces strong immunogenicity against SARS-CoV-2 beta (B.1.351) and other variants of concern in preclinical studies

Background There is an ongoing global effort to design, manufacture, and clinically assess vaccines against SARSCoV-2. Over the course of the ongoing pandemic a number of new SARS-CoV-2 virus isolates or variants of concern (VoC) have been identified containing mutations in key proteins. Methods In this study we describe the generation and preclinical assessment of a ChAdOxi-vectored vaccine (AZD2816) which expresses the spike protein of the Beta VoC (B.1.351). Findings We demonstrate that AZD2816 is immunogenic after a single dose. When AZD2816 is used as a booster dose in animals primed with a vaccine encoding the original spike protein (ChAdOxi nCoV-19/ [AZD1222]), an increase in binding and neutralising antibodies against Beta (B.1.351), Gamma (PA) and Delta (B.1.617.2) is observed following each additional dose. In addition, a strong and polyfunctional T cell response was measured all booster regimens. Interpretation Real world data is demonstrating that one or more doses of licensed SARS-CoV-2 vaccines confer reduced protection against hospitalisation and deaths caused by divergent VoC, including Omicron. Our data support the ongoing clinical development and testing of booster vaccines to increase immunity against highly mutated VoC. Copyright (C) 2022 The Authors. Published by Elsevier B.V.

Automated summary

This study describes the generation and preclinical assessment of a vaccine targeting Beta VoC (B.1.351), which shows immunogenicity after a single dose and produces antibody responses to other variants as a booster, along with a strong T cell response.