A systems immunology study comparing innate and adaptive immune responses in adults to COVID-19 mRNA (BNT162b2/mRNA-1273) and adenovirus vectored vaccines (ChAdOx1-S)

We longitudinally profiled plasma proteomes in 54 adults vaccinated with the BNT162b2 (Pfizer-BioNTech) or ChAdOx1-S (Oxford-AstraZeneca) vaccines. Blood was collected pre-vaccination (V0) and 1-7 days after the 1st doses (BNT162b2 or mRNA-1273, V1) to assess innate and early adaptive responses. We identified key differences in the immune responses induced by the ChAdOx1-S and BNT162b2 vaccines that were correlated with subsequent antigen-specific antibody and T cell responses or vaccine reactogenicity. We observed that vaccination with ChAdOx1-S but not BNT162b2 induced a memory-like response after the first dose, which was correlated with the expression of several proteins involved in complement and coagulation. The COVID-19 Vaccine Immune Responses Study (COVIRS) thus represents a major resource to understand the immunogenicity and reactogenicity of these COVID-19 vaccines.