Evaluation of the immunogenicity of prime-boost vaccination with the replication-deficient viral vectored COVID-19 vaccine candidate ChAdOx1 nCoV-19
Simon P. Graham, Rebecca McLean, Alexandra J. Spencer, Sandra Belij‐Rammerstorfer, Daniel Wright, Marta Ulaszewska, Jane C. Edwards, Jack W. P. Hayes, Veronica Martini, Nazia Thakur, Carina Conceicao, Isabelle Dietrich, Holly Shelton, Ryan Waters, Anna B. Ludi, Ginette Wilsden, Clare Browning, Dagmara Bialy, Sushant Bhat, Phoebe Stevenson-Leggett, Philippa Hollinghurst, Ciarán Gilbride, David Pulido, Katy Moffat, Hannah Sharpe, Elizabeth Allen, Valérie Mioulet, Chris Chiu, Joseph Newman, Amin S. Asfor, Alison Burman, Sylvia Crossley, Jiandong Huo, Raymond J. Owens, Miles W. Carroll, John A. Hammond, Elma Tchilian, Dalan Bailey, Bryan Charleston, Sarah C. Gilbert, Tobias J. Tuthill, Teresa Lambe
Abstract
Clinical development of the COVID-19 vaccine candidate ChAdOx1 nCoV-19, a replication-deficient simian adenoviral vector expressing the full-length SARS-CoV-2 spike (S) protein was initiated in April 2020 following non-human primate studies using a single immunisation. Here, we compared the immunogenicity of one or two doses of ChAdOx1 nCoV-19 in both mice and pigs. Whilst a single dose induced antigen-specific antibody and T cells responses, a booster immunisation enhanced antibody responses, particularly in pigs, with a significant increase in SARS-CoV-2 neutralising titres.