Spike-antibody responses to COVID-19 vaccination by demographic and clinical factors in a prospective community cohort study

Vaccination constitutes the best long-term solution against Coronavirus Disease-2019; however, vaccine-derived immunity may not protect all groups equally, and the durability of protective antibodies may be short. We evaluate Spike-antibody responses following BNT162b2 or ChAdOx1-S vaccination amongst SARS-CoV2-naive adults across England and Wales enrolled in a prospective cohort study (Virus Watch). Here we show BNT162b2 recipients achieved higher peak antibody levels after two doses; however, both groups experience substantial antibody waning over time. In 8356 individuals submitting a sample ≥28 days after Dose 2, we observe significantly reduced Spike-antibody levels following two doses amongst individuals reporting conditions and therapies that cause immunosuppression. After adjusting for these, several common chronic conditions also appear to attenuate the antibody response. These findings suggest the need to continue prioritising vulnerable groups, who have been vaccinated earliest and have the most attenuated antibody responses, for future boosters. Vaccination can provide reliable and long-lasting protection against COVID-19, however the immune response to vaccination can vary between individuals and can decline over time, leading to differences in protective effects. Here the authors assess the immune response to COVID-19 vaccination across a large cohort of previously uninfected adults and demonstrate lower post-vaccination antibody levels amongst those with immune-suppressing conditions and medications, as well as those with several other more common chronic conditions.