Inactivated Split Virus Seasonal Influenza Vaccine(Baxter Healthcare Corporation)

Please cite this paper as: Marra et al. (2012) A Meta‐analysis of intradermal versus intramuscular influenza vaccines: immunogenicity and adverse events. Influenza and Other Respiratory Viruses 7(4), 584–603.Objective  To determine immunogenicity and safety of intradermal (ID) influenza vaccines compared with intramuscular (IM) administration and effect of dose and age.Design  Meta‐anlysis.Setting  Systematic review and meta‐analysis of randomized controlled trials on influenza vaccines.Sample  Randomized, controlled trials comparing ID seasonal split‐virus influenza vaccines with 15 μg IM control in subjects 18 years of age or older and assessed antibody response at 21–28 days post‐vaccination were considered for inclusion.Results  A total of 13 trials were included. The pooled immunogenicity outcomes did not differ significantly between the IM and ID vaccine groups for the H1N1 (ratio of GMTR: 0·92, 95% confidence interval 0·77–1·09; seroconversion: 0·94, 0·86–1·02; seroprotection: 0·97, 0·94–1·00) and B strains (GMTR: 0·93, 0·80–1·08; seroconversion: 0·91, 0·80–1·04; seroprotection: 0·97, 0·91–1·03). For the H3N2 strain, there was no significant difference in GMTR (0·97, 0·80–1·18); however, there was a lower pooled seroconversion (0·89, 0·80–0·99) and seroprotection rate (0·98, 0·96–0·99) for ID recipients. There was a statistically significant association between increasing doses of the ID vaccination with increasing immunogenicity response (P = 0·01). There were no differences in adverse event rates within 3 days post‐vaccination for ID versus IM. But for adverse events occurring 7 days post‐vaccination, ID vaccination was associated with a greater incidence of local events but not systemic events.Conclusions  There was no significant difference in immunologic response when comparing ID with IM administration of the influenza vaccination in the overall population, but higher doses of ID vaccine in the older adult population produced a better response.

Please cite this paper as: Seidman et al. (2012) Quantitative review of antibody response to inactivated seasonal influenza vaccines. Influenza and Other Respiratory Viruses 6(1), 52–62.Background  Seasonal influenza epidemics are associated with significant morbidity and mortality each year, particularly amongst young children and the elderly. Seasonal influenza vaccines have been available for decades, yet influenza remains a major public health threat in the US, sparking interest in studies evaluating the effectiveness of vaccination.Objectives  We sought to identify determinants of serological responses to inactivated seasonal influenza vaccines including number of doses, adjuvant, and subject characteristics.Methods  We reviewed 60 articles published between 1987 and 2006. We used weighted multiple logistic regression and random‐effects models to evaluate how seroconversion and seroprotection rates varied with host and vaccine factors.Results  Both children and seniors tended to have poorer immune responses compared to adults whereas use of adjuvant and a second vaccine dose tended to improve immune response. Pre‐vaccination serological status had a large impact on the immune response to vaccination. We found substantial heterogeneity among studies, even with similar population settings and vaccination regimen.Conclusions  Future studies should stratify their results by pre‐vaccination serological status in an effort to produce more precise summary estimates of vaccine response.