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

• Published in: Nature communications Vol. 13; no. 1; pp. 4610 - 12
• Main Authors: van Doremalen, Neeltje, Schulz, Jonathan E., Adney, Danielle R., Saturday, Taylor A., Fischer, Robert J., Yinda, Claude Kwe, Thakur, Nazia, Newman, Joseph, Ulaszewska, Marta, Belij-Rammerstorfer, Sandra, Saturday, Greg, Spencer, Alexandra J., Bailey, Dalan, Russell, Colin A., Gilbert, Sarah C., Lambe, Teresa, Munster, Vincent J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.08.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 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
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-32248-6

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.