Journal Article

ChAdOx1 nCoV-19 (AZD1222) or nCoV-19-Beta (AZD2816) protect Syrian hamsters against Beta Delta and Omicron variants

Spencer, Alexandra J., van Doremalen, Neeltje, Schulz, Jonathan E., Thakur, Nazia, Russell, Colin A., Lambe, Teresa, Belij-Rammerstorfer, Sandra, Saturday, Taylor A., Yinda, Claude Kwe, Munster, Vincent J., Gilbert, Sarah C., Newman, Joseph, Bailey, Dalan, Fischer, Robert J., Adney, Danielle R., Saturday, Greg, Ulaszewska, Marta

2022

Overview

ChAdOx1 nCoV-19 (AZD1222) is a replication-deficient simian adenovirus–vectored vaccine encoding the spike (S) protein of SARS-CoV-2, based on the first published full-length sequence (Wuhan-1). AZD1222 has been shown to have 74% vaccine efficacy against symptomatic disease in clinical trials. However, variants of concern (VoCs) have been detected, with substitutions that are associated with a reduction in virus neutralizing antibody titer. Updating vaccines to include S proteins of VoCs may be beneficial, even though current real-world data is suggesting good efficacy following boosting with vaccines encoding the ancestral S protein. Using the Syrian hamster model, we evaluate the effect of a single dose of AZD2816, encoding the S protein of the Beta VoC, and efficacy of AZD1222/AZD2816 as a heterologous primary series against challenge with the Beta or Delta variant. Minimal to no viral sgRNA could be detected in lungs of vaccinated animals obtained at 3- or 5- days post inoculation, in contrast to lungs of control animals. In Omicron-challenged hamsters, a single dose of AZD2816 or AZD1222 reduced virus shedding. Thus, these vaccination regimens are protective against the Beta, Delta, and Omicron VoCs in the hamster model. Whilst the ChAdOx1 nCoV-19 (AZD1222) vaccine has demonstrated efficacy against symptomatic disease, variants of concern (VOCs) with spike protein substitutions have led researchers to explore updating vaccines from ancestral spike protein. Authors use a Syrian hamster model to evaluate a vaccine encoding the spike protein of Beta VOC and assess efficacy against VOCs.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 13/1 / 13/106 / 13/21 / 45/88 / 45/90 / 631/326/590/1962 / 631/326/596/4130 / 82/1 / Animals / Antibodies / Antibodies, Viral / ChAdOx1 nCoV-19 / Clinical trials / COVID-19 - prevention & control / Cricetinae / Evaluation / Hamsters / Humanities and Social Sciences / Humans / Immunization / Inoculation / Lungs / Mesocricetus / multidisciplinary / Proteins / SARS-CoV-2 / Science / Science (multidisciplinary) / Severe acute respiratory syndrome coronavirus 2 / Spike protein / Vaccine efficacy / Vaccines / Viral diseases / Viral Vaccines / Viruses