Older Adults Mount Less Durable Humoral Responses to a Two-dose COVID-19 mRNA Vaccine Regimen, but Strong Initial Responses to a Third Dose.

ABSTRACT:

Background

Third COVID-19 vaccine doses are broadly recommended, but immunogenicity data remain limited, particularly in older adults.

Methods

We measured circulating antibodies against the SARS-CoV-2 spike protein receptor-binding domain, ACE2 displacement, and virus neutralization against ancestral and Omicron (BA.1) strains from pre-vaccine up to one month following the third dose, in 151 adults aged 24-98 years who received COVID-19 mRNA vaccines.

Results

Following two vaccine doses, humoral immunity was weaker, less functional and less durable in older adults, where a higher number of chronic health conditions was a key correlate of weaker responses and poorer durability. Third doses boosted antibody binding and function to higher levels than second-doses, and in

SUBMITTER: Mwimanzi F 

PROVIDER: S-EPMC8750654 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature