Decreased antibody titers and booster responses in tick-borne encephalitis vaccinees aged 50–90 years

Immunization in the adult immunocompromised host

The number of patients with impaired immune response has been steadily increasing within the last years, not only with the onset of the AIDS epidemic, but also due to increasing numbers of subjects on immunosuppressive therapies. These patients are at an increased risk for infections, many of which are preventable by immunization. Inactivated vaccines are generally safe in subjects with underlying immunosuppression. However, immune response and protection may be hampered, depending on the extent of immunosuppression. In contrast, live vaccines such as yellow fever, measles, rubella, herpes zoster, and cholera may lead to severe reactions in immunocompromised patients and have been shown to deteriorate some immune-mediated diseases such as multiple sclerosis. Data on the efficacy of vaccines in biological therapies is scarce. Where necessary vaccines should be updated before immunosuppressive therapies are started. To improve the vaccination status several guidelines exist for immunosuppressed patients at risk such as those with rheumatic diseases, asplenia or solid organ and hematopoietic stem cell transplantation.

Immunologic non-inferiority of a newly licensed inactivated trivalent influenza vaccine versus an established vaccine: a randomized study in US adults

A trivalent inactivated influenza vaccine (Fluarix (™) , GlaxoSmithKline Biologicals) was licensed under US accelerated approval regulations. We performed a randomized, observer-blind, post-approval study to demonstrate its immunological non-inferiority versus an established US-licensed vaccine (primary endpoint). Adult (including elderly) subjects received a single injection of newly-licensed vaccine (n = 923) or established vaccine (n = 922). Serum hemagglutination-inhibition titers were determined pre-vaccination and 21-28 days after vaccination. Non-inferiority was assessed by post-vaccination geometric mean titer (GMT) ratio (upper 95% confidence interval [CI] ≤ 1.5) and difference in seroconversion rate (upper 95% CI ≤ 0.1) for all three vaccine strains. Safety was monitored for 6 months. The newly-licensed vaccine was non-inferior to the established vaccine in all subjects (≥ 18 years) and in elderly subjects (≥ 65 years). Adjusted GMT ratios (established/newly-licensed) against the H1N1, H3N2 and B strains were 0.65 (95% CI: 0.58, 0.73), 0.93 (0.83, 1.04) and 1.13 (1.03, 1.25) for all subjects and 0.75 (0.67, 0.85), 0.95 (0.82, 1.09) and 1.13 (1.00, 1.27) for elderly subjects. Corresponding values for the differences in seroconversion rate (established minus newly-licensed) were -0.12 (-0.16, -0.07), -0.02 (-0.06, 0.03) and 0.01 (-0.04, 0.06) for all subjects and -0.11 (-0.16, -0.05), -0.02 (-0.07, 0.04) and 0.02 (-0.04, 0.08) for elderly subjects. The most common adverse events with both vaccines were injection site pain, fatigue and headache, and no serious adverse events or deaths were considered related; there were no clinically relevant differences between the vaccines. In conclusion, the newly-licensed vaccine was well tolerated and immunologically non-inferior to the established vaccine for all three vaccine strains in the whole population and the elderly.