Antibody Responses after Influenza Vaccination in Elderly People: Useful Information from a 27-Year Study (from 1988– 1989 to 2014–2015)

Elderly people are more likely than younger people to get flu complications and respond suboptimally to influenza vaccination because of the presence of comorbidities and immunosenescence. In order to collect information about this issue, we evaluated data obtained in 27 winters of study, from 1988–1989 to 2014–2015, in frail elderly institutionalized people (≥60 years) vaccinated with commercially available seasonal trivalent inactivated influenza vaccines. The antibody response was examined comparing hemagglutination inhibition antibody titers in sera collected from 4461 volunteers before and 30 days after vaccination. Examining the results as crude mean responses, we evidenced the ability of influenza vaccines to induce significant increases in antibody titers against all the three vaccine antigens satisfying at least one of the three criteria of the Committee for Medical Products for Human Use (CHMP). Higher responses were found against A/H3N2 vaccine components and, examining different subgroups, in volunteers receiving 45 μg vaccine as compared with 30 μg and in female as compared with male subjects. Very elderly people (>75 years) gave better responses than younger elderly (≤75 years) at least against A/H1N1 strain and the last licensed potentiated vaccines (MF59-adjuvanted and intradermal) were more immunogenic than traditional vaccines (whole, subunit, and split)

Induction of Cross-Reactive Antibodies to 2009 Pandemic H1N1 Influenza Virus (pH1N1) After Seasonal Vaccination (Winters 2003/04 and 2007/08)

Abstract We measured haemagglutination inhibiting (HI) serum antibody titers to vaccine matched A/H1N1 influenza virus strain and to the new pandemic 2009 A/H1N1 (pH1N1) virus in two groups of volunteers prior and after 2003/2004 or 2007/2008 influenza seasonal vaccine administration. The responses were examined considering the overall volunteers studied in the two winters (144 and 79, respectively) and grouping those subjects in birth cohort classes (1903–1919; 1920–1957; 1958–1977). Before vaccination, HI antibody titers were found in all the groups examined and, on comparing the different age-groups, titers were higher in the younger groups as compared with the oldest against the A/H1N1 seasonal strains but titers were higher in the oldest as compared with the younger ones against the pH1N1 strain. Vaccination induced significant increases in HI titers against the matched A/H1N1 vaccine strains in all the groups examined. The responses satisfied the EMEA criteria and were higher in the youngest volunteers as compared with older groups. Increases were also found in the level of cross-reactive HI antibodies to the new pandemic 2009 A/H1N1 virus although in most instances the requirements of the EMEA were not met

Comparative Study of Immunogenicity of Split, Intradermal and MF59-adjuvanted Influenza Vaccines in Elderly Institutionalized Subjects

Abstract The reduced immunogenicity and effectiveness of influenza vaccines in subjects presenting high risk of influenza-related complications, hospitalization and death, led the innovative drive to search for new strategies to implement the immune response elicited by influenza vaccines including addition of adjuvants, and use of alternative routes of antigen delivery.In this study we evaluated and compared the immune antibody response induced in 252 elderly volunteers living in nursing homes after immunization with three different 2012-2013 seasonal trivalent inactivated influenza vaccines: a conventional split vaccine (n=26), and two potentiated vaccines (a subunit vaccine adjuvanted with MF59 (n=137) or a split vaccine administered intradermally (n=89)), specially licensed for elderly people. Haemagglutination inhibiting (HI) antibody titers were assessed in blood samples collected before and one month after vaccination.The results were evaluated as increase in HI titers found comparing pre- and post-vaccination sera and according to the Committee for Medicinal Products for Human Use (CHMP) criteria for approval of influenza vaccines in the elderly. Significant antibody increases and fulfillment of all the three CHMP requirements were observed against A/H3N2 and B antigens following immunization with the two potentiated vaccines. After immunization with conventional vaccine responses were lower against A/H3N2 and equivalent against the B antigen. The two potentiated vaccines induced significant antibody increases against A/H1N1 antigen, however, only one of the CHMP criteria was reached. The HI antibody increases after conventional vaccine were significant only for the geometric mean titer and none of the CHMP criteria was fulfilled. The antibody responses induced by the two potentiated vaccines against the three vaccine antigens wereequivalent although post-vaccination titers against the B antigen tended to be higher in subjects vaccinated with intradermal vaccine than in individuals receiving MF59-adjuvanted vaccine. In conclusion the use of MF59 adjuvant and intradermal vaccination appear to be appropriate strategies to address the challenge of declining immune response in the elderly after influenza vaccination

Comparison of the BD Phoenix System with the Cefoxitin Disk Diffusion Test for Detection of Methicillin Resistance in Staphylococcus aureus and Coagulase-Negative Staphylococci▿

The BD Phoenix system was compared to the cefoxitin disk diffusion test for detection of methicillin (meticillin) resistance in 1,066 Staphylococcus aureus and 1,121 coagulase-negative staphylococcus (CoNS) clinical isolates. The sensitivity for Phoenix was 100%. The specificities were 99.86% for S. aureus and 88.4% for CoNS