Vaccine
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The serological response of the current 2009 H1N1 pandemic influenza monovalent vaccine in children exhibiting high baseline seropositive rate was evaluated though a community-based household study. Seroprotection rate of >90% and seroconversion rate of >50% were observed in children one month after receiving the pandemic vaccine. Among children with low baseline antibody titer, a significant lower seroconversion rate (55%) was observed in children who received seasonal trivalent inactivated vaccine (TIV) prior to pandemic vaccine, when compared with those receiving the pandemic vaccine only (86%). Persistence of antibody against the pandemic influenza virus was observed 6 months after vaccination in >80% of children presenting seroprotective antibody levels.
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To identify studies of influenza vaccination of HCWs and influenza in elderly residents in long-term care facilities. ⋯ The key outcomes are serologically proven influenza, pneumonia, and deaths from pneumonia, and pooled data from three C-RCTs showed no effect. Pooled data from three C-RCTs showed lower resident all-cause mortality, but as influenza constituted less than 10% of all deaths even in epidemic years we question the appropriateness of this outcome measure. Pooled data from three C-RCTs showed vaccination of HCWs reduced ILI and data from one C-RCT that HCW vaccination reduced GP consultations for ILI, but as influenza constitutes less than 25% of ILI and we did not show that HCW influenza vaccination reduced serologically proven influenza we question whether this effect is due to confounding.
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Some vaccines show poor efficacy in tropical countries. Within a birth cohort in Uganda, we investigated factors that might influence responses to BCG and tetanus immunisation. Whole blood assay responses to crude culture filtrate proteins of Mycobacterium tuberculosis (cCFP)) and tetanus toxoid (TT) were examined among 1506 and 1433 one-year-olds, respectively. ⋯ We conclude that maternal helminth infections are unlikely to explain poor vaccine efficacy in the tropics. Effects of maternal immunisation on infant responses to vaccines should be explored. Prevention of infant malaria and HIV could contribute to effectiveness of immunisation programmes.
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Randomized Controlled Trial
A replication defective recombinant Ad5 vaccine expressing Ebola virus GP is safe and immunogenic in healthy adults.
Ebola virus causes irregular outbreaks of severe hemorrhagic fever in equatorial Africa. Case mortality remains high; there is no effective treatment and outbreaks are sporadic and unpredictable. Studies of Ebola virus vaccine platforms in non-human primates have established that the induction of protective immunity is possible and safety and human immunogenicity has been demonstrated in a previous Phase I clinical trial of a 1st generation Ebola DNA vaccine. ⋯ Thirty-one healthy adults received vaccine at 2×10(9) (n=12), or 2×10(10) (n=11) viral particles or placebo (n=8) as an intramuscular injection. Antibody responses were assessed by ELISA and neutralizing assays; and T cell responses were assessed by ELISpot and intracellular cytokine staining assays. This recombinant Ebola virus vaccine was safe and subjects developed antigen specific humoral and cellular immune responses.