Abstract
The impact of previous SARS-CoV-2 infection on the durability of Ad26.COV2.S vaccine-elicited responses, and the effect of homologous boosting has not been well explored. We followed a cohort of healthcare workers for 6 months after receiving the Ad26.COV2.S vaccine and a further one month after they received an Ad26.COV2.S booster dose. We assessed longitudinal spike-specific antibody and T cell responses in individuals who had never had SARS-CoV-2 infection, compared to those who were infected with either the D614G or Beta variants prior to vaccination. Antibody and T cell responses elicited by the primary dose were durable against several variants of concern over the 6 month follow-up period, regardless of infection history. However, at 6 months after first vaccination, antibody binding, neutralization and ADCC were as much as 59-fold higher in individuals with hybrid immunity compared to those with no prior infection. Antibody cross-reactivity profiles of the previously infected groups were similar at 6 months, unlike at earlier time points, suggesting that the effect of immune imprinting diminishes by 6 months. Importantly, an Ad26.COV2.S booster dose increased the magnitude of the antibody response in individuals with no prior infection to similar levels as those with previous infection. The magnitude of spike T cell responses and proportion of T cell responders remained stable after homologous boosting, concomitant with a significant increase in long-lived early differentiated CD4 memory T cells. Thus, these data highlight that multiple antigen exposures, whether through infection and vaccination or vaccination alone, result in similar boosts after Ad26.COV2.S vaccination.
Funder
South African Medical Research Council
Department of Science and Innovation, South Africa
National Research Foundation South Africa
Centre for the AIDS Programme of Research in South Africa
Bill and Melinda Gates Foundation
Poliomyelitis Research Foundation
Wellcome Centre for Infectious Diseases Research in Africa
European Union’s Horizon 2020 programme
Wellcome Trust
National Institutes of Health
Medical Research Council
Lily and Ernst Hausmann Trust
Publisher
Public Library of Science (PLoS)
Subject
Virology,Genetics,Molecular Biology,Immunology,Microbiology,Parasitology
Reference52 articles.
1. Safety and efficacy of single-dose Ad26. COV2. S vaccine against Covid-19;J Sadoff;New England Journal of Medicine,2021
2. Interim Results of a Phase 1–2a Trial of Ad26. COV2. S Covid-19 Vaccine;J Sadoff;New England Journal of Medicine,2021
3. Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: results of a systematic review and meta-regression;DR Feikin;The Lancet,2022
4. Effectiveness of Ad26.COV2.S and BNT162b2 Vaccines against Omicron Variant in South Africa;G Gray;New England Journal of Medicine,2022
5. Effectiveness of Covid-19 Vaccines over a 9-Month Period in North Carolina;D-Y Lin;New England Journal of Medicine,2022