Vaccine
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Seven-valent pneumococcal conjugate vaccine (PCV7) was introduced into the South African immunization program using 6, 14 and 40 weeks dosing schedule (2+1), with no catch-up in older children since April 2009. We investigated pneumococcal colonization acquisition in children who received this schedule and also compared it to historical cohorts of PCV-naïve children (n=123 in 2007) and children who received a 3+1 PCV7 schedule (n=124 in 2005/06). ⋯ A 2+1 PCV7 schedule implemented in South Africa was temporally associated with reduced risk of vaccine-serotype colonization compared to historically unvaccinated children. Also, vaccine-serotype acquisition rate using the 2+1 schedule was similar to that in the 3+1 dosing cohort, suggesting that similar indirect protection against pneumococcal disease could be derived from either schedule in South Africa.
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To empower governments to formulate rational policies without pressure from any group, and to increase the use of evidence-based decision-making to adapt global recommendations on immunization to their local context, the WHO has recommended on multiple occasions that countries should establish National Immunization Technical Advisory Groups (NITAGs). The World Health Assembly (WHA) reinforced those recommendations in 2012 when Member States endorsed the Decade of Vaccines Global Vaccine Action Plan (GVAP). NITAGs are multidisciplinary groups of national experts responsible for providing independent, evidence-informed advice to health authorities on all policy-related issues for all vaccines across all populations. ⋯ In addition to providing direct support to countries to establish advisory groups, the initiative also supports existing NITAGs to strengthen their capacity in the use of evidence-based processes for decision-making aligned with international standards. After 5 years of implementation and based on lessons learned, we recommend that future efforts should target both expanding new NITAGs and strengthening existing NITAGs in individual countries, along three strategic lines: (i) reinforce NITAG institutional integration to promote sustainability and credibility, (ii) build technical capacity within NITAG secretariats and evaluate NITAG performance, and (iii) increase networking and regional collaborations. These should be done through the development and dissemination of tools and guidelines, and information through a variety of adapted mechanisms.
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In March 2009, the U.S. Food and Drug Administration licensed an inactivated, Vero cell culture-derived Japanese encephalitis vaccine (JE-VC [Ixiaro]) for use in adults. The vaccine was licensed based on clinical trial safety data in 3558 JE-VC recipients. It is essential to monitor post-licensure surveillance data to evaluate the safety of JE-VC because rare adverse events may not be detected until the vaccine is administered to a larger population. ⋯ These post-marketing surveillance data suggest a good safety profile for JE-VC consistent with findings from pre-licensure clinical trials. Post-licensure safety data should continue to be monitored for any evidence of rare serious or neurologic adverse events.
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Randomized Controlled Trial Clinical Trial
Immunogenicity of heterologous H5N1 influenza booster vaccination 6 or 18 months after primary vaccination in adults: a randomized controlled clinical trial.
Highly pathogenic avian influenza A/H5N1 viruses continue to circulate in birds and infect humans causing serious illness and death. ⋯ Adults primed with a dose-sparing oil-in-water adjuvanted H5N1 subclade vaccine had rapid and durable antibody responses to a heterologous subclade boosting vaccine given 6 or 18 months later.
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Since protective efficacy of the current typhoid vaccines-oral whole-cell Salmonella Typhi Ty21a and parenteral Vi-capsular polysaccharide preparation-is not optimal, and no vaccines are available against paratyphoid or non-typhoidal Salmonella (NTS) serotypes, new approaches deserve to be explored. The immunological mechanisms elicited by the two typhoid vaccines are mainly targeted against different structures. We studied whether these vaccines would enhance S. Typhi-specific immune response and cross-reactivity against other Salmonellae, if administered concomitantly. ⋯ Concomitant administration of Ty21a and Vi vaccines is well tolerated and induces an additive immune response to the two vaccines. Thus it enhances the magnitude of both typhoid-specific plasmablast responses and those cross-reacting with paratyphoid and most important NTS serotypes. The data encourage concomitant use of Ty21 and Vi vaccines for those at risk.