Self-reported diabetes and herpes zoster are associated with a weak humoral response to the seasonal influenza A H1N1 vaccine antigen among the elderly

Table 3 Crude and weighted prevalence rates of weak humoral response to an adjuvanted influenza vaccine among the elderly^d

Vaccine strains	Proportion of individuals with a weak humoral response^a, % (95% CI^b)	Weighted proportion of individuals with a weak humoral response, %^c
A H1N1	49.0 (42.2–55.9)	49.3
A H3N2	13.5 (9.4–18.9)	12.5
B	37.0 (30.6–43.9)	36.1

^aResponders to the respective components of the influenza vaccine are those who had a ≥ 4-fold HAI titer increase between day 0 and day 21 with respect to the time of vaccination. Nonresponders are those who did not have a fourfold titer increase
^b95% approximate binomial confidence intervals (CI) were calculated according to Wilson
^cPost-stratification weights were calculated with respect to sex and age to obtain nationally representative estimates. The sex and age distribution of the general German population in the respective year was obtained from the Federal Statistical Office
^dFluad®, an inactivated trivalent influenza vaccine adjuvanted with MF59® recommended for the respective influenza season, was used

ISSN: 1471-2334