Head-to-head comparison of an intradermal and a virosome influenza vaccine in patients over the age of 60: Evaluation of immunogenicity, cross-protection, safety and tolerability.
ABSTRACT In the present study we first compare immunogenicity against vaccine and heterologous circulating A(H1N1)pdm09 strains, tolerability and safety of intradermal Intanza® 15 µg and of virosomal adjuvanted, intramuscularly delivered influenza vaccine, Inflexal® V, in healthy elderly volunteers. Five-hundred participants were enrolled in the study and randomly assigned to the two vaccine groups to receive either one dose of Intanza® 15 µg or Inflexal® V vaccine. All subjects reported solicited local and systemic reactions occurred within 7 d after vaccination and unsolicited adverse events up to 21 d post-immunization and any serious adverse event appeared during the study. A subset of 55 participants was randomly selected for immunogenicity and cross-protection evaluations. Serum samples were collected before and 1 and 3 mo after immunization. Antibody responses were measured using hemagglutination inhibition (HI) against all viruses used in the study and neutralization (NT) assays against A(H1N1)pdm09 strains. At least one of the CHMP criteria for influenza vaccine approval in the elderly was met by virosomal vaccine against all the tested viruses; intradermal vaccine met all criteria against all strains. Several parameters of immune response against strains with a different antigenic pattern from that of vaccine A/California/04/09(H1N1)pdm09 were significantly higher in the intradermal vaccine group compared with the virosomal group. Safety and systemic tolerability of both vaccines were excellent, but injection site reactions occurred significantly more frequently in the intradermal vaccination group. Immunogenicity of Intanza® 15 µg intradermal vaccine tended to be higher than that of Inflexal® V against heterologous strains in healthy elderly.
SourceAvailable from: Michela Basileo[Show abstract] [Hide abstract]
ABSTRACT: The age-related weakening of the immune system makes elderly subjects less responsive to influenza vaccination. In the last years, two "enhanced vaccines" were licensed for individuals aged ≥65 years, one being a subunit vaccine (Fluad®) containing the MF59 adjuvant administered intramuscularly (IM-MF59) and the other one a split non-adjuvanted vaccine administered intradermally (Intanza® 15mcg) (ID). In the present study, we evaluated and compared the antibody responses against the three vaccine antigens and heterovariant A(H3N2) circulating viruses induced by IM-MF59 and ID influenza vaccines in 80 elderly institutionalized volunteers (40 per group) during the Winter season 2011-2012.Immunity & Ageing 05/2014; 11:10. DOI:10.1186/1742-4933-11-10 · 2.32 Impact Factor
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ABSTRACT: The immune system of the elderly is particularly susceptible to infectious diseases and displays reduced response to vaccination. The current vaccines, designed for young and adult individuals, proved less effective and less protective in old people. The world population is rapidly ageing, and consequently preventing infectious diseases in the elderly has become an important public health issue. To this end, it is necessary to develop novel vaccines especially suited to raising protective immunity in the ageing population. Approaches in this direction include high-dose vaccines, booster vaccinations, different immunisation routes, and use of new adjuvants. These approaches, still empirical, must be supported by intensive research to unravel the biological and molecular mechanisms underlying immunosenescence. Only this knowledge would allow us to design approaches to immune rejuvenation and more effective vaccines for protecting the elderly.Immunology Letters 06/2014; DOI:10.1016/j.imlet.2014.06.006 · 2.37 Impact Factor
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ABSTRACT: Background: The use of intradermal vaccination or virosomal vaccines could increase protection against influenza among the vulnerable population of older adults. Studies assessing the comparative effectiveness of these two influenza vaccine types in this age group are lacking. Methods: We conducted a retrospective cohort study to estimate the comparative effectiveness of intradermal seasonal trivalent-influenza vaccine (TIV) delivered by a microneedle injection system and a virosomal-TIV intramuscularly delivered for prevention of influenza hospitalization in non-institutionalized adults aged >= 65 years. We obtained administrative data on immunization status and influenza hospitalization for the 2011-2012 influenza season, and used Cox regression models to assess comparative effectiveness. We estimated crude and adjusted (age, sex, comorbidity, pharmaceutical claims, recent pneumococcal vaccination and number of hospitalizations for all causes other than influenza between the previous and current influenza seasons) hazard ratios (HR). Results: Overall, 164,021 vaccinated subjects were evaluated. There were 127 hospitalizations for influenza among 62,058 subjects, contributing 914,740 person-weeks at risk in the virosomal-TIV group, and 133 hospitalizations for influenza among 101,963 subjects, contributing 1,504,570 person-weeks at risk in the intradermal-TIV group. The crude HR of intradermal-TIV relative to virosomal-TIV was 0.64 (95% confidence interval (CI): 0.50-0.81), and the adjusted Cox estimated HR was 0.67(95% CI: 0.52-0.85). Conclusions: During the 2011-2012 influenza season the risk of hospitalization for influenza was reduced by 33% in non-institutionalized elderly adults who were vaccinated with intradermal-TIV compared with virosomal-TIV. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.Vaccine 08/2014; 32(42). DOI:10.1016/j.vaccine.2014.07.095 · 3.49 Impact Factor