Factors associated with humoral immune response in older adults who received egg-free influenza vaccine.

ABSTRACT:

Background

Immune responses to influenza vaccination tend to be lower among older, frequently vaccinated adults. Use of egg-free influenza vaccines is increasing, but limited data exist on factors associated with their immunogenicity in older adults.

Methods

Community-dwelling older adults ≥ 56 years of age were enrolled in a prospective, observational study of immunogenicity of 2018-2019 influenza vaccine. Hemagglutination inhibition (HAI) antibody titers were measured pre-vaccination (Day 0) and four weeks after vaccination (Day 28) to calculate geometric mean titers, seropositivity (HAI titers ≥ 1:40), seroconversion (fourfold rise in HAI titer with post-vaccination titer ≥ 1:40) and geometric mean fold rise (GMFR). Linear regression models assessed the association of pre

SUBMITTER: Williams KV 

PROVIDER: S-EPMC9850444 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature