Frailty is associated with impairment of vaccine-induced antibody response and increase in post-vaccination influenza infection in community-dwelling older adults

Abstract

Annual immunization with a trivalent inactivated vaccine (TIV) is considered efficacious for prevention of seasonal influenza in older adults. However, significant controversy exists in the current literature regarding the clinical effectiveness of TIV immunization in this highly heterogeneous population. Frailty is an important geriatric syndrome characterized by decreased physiologic reserve and increased vulnerability to stressors. Using a validated set of frailty criteria, we conducted a prospective observational study to evaluate TIV-induced strain-specific hemagglutination inhibition (HI) antibody titers and post-vaccination rates of influenza-like illness (ILI) and infection in frail and nonfrail older adults. The results indicate that frailty was associated with significant impairment in TIV-induced strain-specific HI titers and increased rates of ILI and laboratory-confirmed influenza infection. These findings suggest that assessing frailty status in the elderly may identify those who are less likely to respond to TIV immunization and be at higher risk for seasonal influenza and its complications.

Copyright © 2011 Elsevier Ltd. All rights reserved.

Figures

Fig. 1

Pre-vaccination screening and blood draw, TIV immunization, as well as post-vaccination blood draw and influenza surveillance.

Fig. 2

GMT ratios to H1N1, H3N2, and B strains in all study participants “All (n = 71)”, nonfrail (n = 22), prefrail (n = 32), and frail (n = 17) groups. p Values were derived from linear regression analysis for stepwise trend of decrease in nonfrail, prefrail, to frail study groups, adjusted for age.

Fig. 3

Rates of influenza-like illness (ILI) (A) and laboratory confirmed influenza infection (B) during post-vaccination season. p Values were obtained from logistic regression analysis for stepwise trend of increase in nonfrail, prefrail, to frail study groups, adjusted for age.