Neutralizing antibody durability and SARS-CoV-2 infection in older adults six months after XBB-containing vaccine booster.

ABSTRACT: The persistence of XBB-containing vaccine-induced immunity against evolving SARS-CoV-2 variants remains uncertain, particularly in older adults, who are at increased risk of severe outcomes and may experience more rapid immune decline. We previously reported neutralizing antibody (nAb) responses 21 days after a single booster dose of trivalent XBB.1.5 (Tri‑XBB.1.5), bivalent Omicron XBB (Bi‑Omi‑XBB), or tetravalent XBB.1 (Tetra‑XBB.1) vaccines in a cohort of 90 older adults aged >65 years. In this six-month longitudinal follow-up analysis of the same cohort, we assessed nAb durability and SARS-CoV-2 infections to extend our earlier findings. Six months post-vaccination, the nAb titers decreased over time, with 2.5‒4.6-fold reductions in the geometric mean titer against the variants KP.3.1.

SUBMITTER: Chen RR 

PROVIDER: S-EPMC12508101 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature