Vaccine
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South Africa has a functional decision making process for the introduction of new vaccines; with an established National Immunisation Technical Advisory Group (NITAG), referred to as National Advisory Group on Immunisation (NAGI). South Africa has played a leadership role in the African continent with introduction of new vaccines, which dates back to 1995 with the introduction of hepatitis B, followed by the Haemophilus influenzae type b in 1999 and recently the national roll out of the pneumococcal conjugate and rotavirus vaccines in 2009. NAGI has the responsibility to deliberate on key policy issues as part of the process for decision making on the introduction of new vaccines. ⋯ A system should be developed to allow the NDOH, NAGI and the MOF to engage in the deliberations on financial and economic impact of new vaccines. It is further recommended that a committee be established that will assess the programmatic issues to weigh the potential benefits of a new vaccine. Furthermore, political commitment should support the immunisation programme and strengthen it so that it can make an impact in the achievement of the Millennium Development Goal no. 4 of reducing child mortality.
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Randomized Controlled Trial
Immunogenicity and safety of tetravalent dengue vaccine in 2-11 year-olds previously vaccinated against yellow fever: randomized, controlled, phase II study in Piura, Peru.
In a randomized, placebo-controlled, monocenter, observer blinded study conducted in an area where dengue is endemic, we assessed the safety and immunogenicity of a recombinant, live, attenuated, tetravalent dengue vaccine candidate (CYD-TDV) in 2-11 year-olds with varying levels of pre-existing yellow-fever immunity due to vaccination 1-7 years previously. 199 children received 3 injections of CYD-TDV (months 0, 6 and 12) and 99 received placebo (months 0 and 6) or pneumococcal polysaccharide vaccine (month 12). One month after the third dengue vaccination, serotype specific neutralizing antibody GMTs were in the range of 178-190 (1/dil) (versus 16.7-38.1 in the control group), a 10-20 fold-increase from baseline, and 94% of vaccines were seropositive to all four serotypes (versus 39% in the control group). ⋯ Virologically confirmed dengue cases were seen after completion of the 3 doses: 1 in the CYD-TDV group (N=199), and 3 in the control group (N=99). A 3-dose regimen of CYD-TDV had a good safety profile in 2-11 year olds with a history of YF vaccination and elicited robust antibody responses that were balanced against the four serotypes.
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Bordetella bronchiseptica, a gram-negative bacterium, causes chronic respiratory tract infections in a wide variety of mammalian hosts, including man, and no human vaccine is currently available. Acellular pertussis vaccines protect poorly against B. bronchiseptica, although they contain cross-reactive antigens. We have recently developed Bordetella pertussis BPZE1, a novel, live attenuated pertussis vaccine, currently completing phase I clinical trials in humans, and found that it protects against both B. pertussis and Bordetella parapertussis in mice. ⋯ In addition, the B. bronchiseptica load was significantly decreased in the vaccinated animals. Using passive transfer experiments, protection was found to be essentially cell mediated, and BPZE1-induced Th1 and Th17 T cells recognize whole B. bronchiseptica extracts, although the participation of antibodies in protection cannot be discounted. Thus, a single administration of BPZE1 can confer protection against B. bronchiseptica in mice by a dual mechanism.
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Multicenter Study
Effectiveness of pandemic and seasonal influenza vaccines in preventing pandemic influenza-associated hospitalization.
Vaccines are leading pharmacological measures for limiting the impact of pandemic influenza in the community. The objective of this study was to investigate the effectiveness of influenza (pandemic and seasonal) vaccines in preventing pandemic influenza-associated hospitalization. We conducted a multicenter matched case-control study in 36 Spanish hospitals. ⋯ For the pandemic influenza vaccine, vaccination effectiveness (VE) was estimated taking into account only patients recruited from November 23, 2009, seven days after the beginning of the pandemic influenza vaccination campaign. 638 cases and 1250 controls were included. The adjusted VE of the pandemic vaccine in the ≥18 years age group was 74.2% (95% CI, 29-90) and that of the influenza seasonal vaccine 15.0% (-34 to 43). The recommendation of influenza vaccination should be reinforced as a regular measure to reduce influenza-associated hospitalization during pandemics and seasonal epidemics.