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

Spencer, Alexandra J; Morris, Susan; Ulaszewska, Marta; Powers, Claire; Kailath, Reshma; Bissett, Cameron; Truby, Adam; Thakur, Nazia; Newman, Joseph; Allen, Elizabeth R; Rudiansyah, Indra; Liu, Chang; Dejnirattisai, Wanwisa; Mongkolsapaya, Juthathip; Davies, Hannah; Donnellan, Francesca R; Pulido, David; Peacock, Thomas P.; Barclay, Wendy S.; Bright, Helen; Ren, Kuishu; Screaton, Gavin; McTamney, Patrick; Bailey, Dalan; Gilbert, Sarah C; Lambe, Teresa

There is an ongoing global effort to design, manufacture, and clinically assess vaccines against SARS-CoV-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. In this study we describe the generation and preclinical assessment of a ChAdOx1-vectored vaccine (AZD2816) which expresses the spike protein of the Beta VoC (B.1.351). 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 (ChAdOx1 nCoV-19/ [AZD1222]), high titre binding and neutralising antibodies against Beta (B.1.351), Gamma (P.1) and Delta (B.1.617.2) are induced. In addition, a strong and polyfunctional T cell response was measured in these booster regimens. These data support the ongoing clinical development and testing of this new variant vaccine.