Durable T cell responses contrast with faster antibody waning in BNT162b2-vaccinated elderly at 6 month

Abstract

Efficient COVID-19 vaccines have been developed in record time. Here, we present findings from a comprehensive and integrated analysis of multiple compartments of the memory immune response in 312 individuals vaccinated with the BNT162b2 mRNA vaccine. Two vaccine doses induced high antibody and T cell responses in most individuals. However, antibody recognition of the Spike protein of delta variant was less efficient than that of the Wuhan strain. Age stratified analyses identified a group of low antibody responders where individuals ≥ 60 years were overrepresented. Waning of the antibody and cellular responses was observed in 30% of the vaccinees after six months. However, age did not influence the waning of these responses. Taken together, while individuals ≥ 60 years old took longer to acquire vaccine-induced immunity, they develop more sustained acquired immunity at six months post-vaccination. However, the higher proportion of older individuals in the group of antibody low responders and the lower antibody reactivity the Delta variant call for a booster immunization to increase immune responses and protection.

SARS-CoV-2 variants of concern and vaccine escape, from Alpha to Omicron and beyond

“…Correspondingly, the rate of waning immunity post-vaccination also varies greatly. Second, there are also important host factors, which determine the strength of immune response to vaccination, rate of waning, and susceptibility to symptomatic and severe infection [ 18 ]. These are highly correlated, such that advanced age, male sex, and comorbid conditions place individuals at highest risk of both severe infection intrinsically and a weaker vaccine-induced immune response, which further increases disease severity.…”