Effect of COVID-19 vaccine platform
DISEASE, VIRUS, SARS-COV-2 INFECTION
Our finding that ChAdOx1-S induced higher anti-spike IgG levels compared to CoronaVac may be explained by the fact that this vaccine is an attenuated virus vector, which activates a broader range of T cells and induces a stronger cytokine production (COVID-19 vaccines are a vital tool in protecting against the disease and particularly severe forms. Randomised control trials (RCTs) of ChAdOx1-S have reported an overall protective efficacy of 81% (Phase III RCTs of CoronaVac have reported protective efficacy varying between 51% in Brazil (Used in an emergency, CoronaVac was approved for vaccination in healthcare workers due to direct contact with COVID-19 patients, leading to higher SARS-CoV-2 exposure than the general population. In a recent cohort study of healthcare workers in Brazil, seropositivity for anti-spike IgG was 99.8% 30 days after the second dose of CoronaVac, and decreased to 97.9% six months after the second doses was 97.0-100% (Prior SARS-CoV-2 infection is associated with stronger responses to COVID-19 vaccines (