两种半球流感疫苗的推荐都将错过马达加斯加近一半的循环病毒。
Both hemispheric influenza vaccine recommendations would have missed near half of the circulating viruses in Madagascar.
机构信息
National Influenza Centre, Virology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.
National Institutes of Health Library, Office of Research Services, Office of Management, National Institutes of Health, Bethesda, MD, USA.
出版信息
Influenza Other Respir Viruses. 2017 Nov;11(6):473-478. doi: 10.1111/irv.12517.
BACKGROUND
Influenza immunization still poses a critical challenge globally and specifically for tropical regions due to their complex influenza circulation pattern. Tropical regions should select the WHO's Northern Hemisphere or Southern Hemisphere recommended vaccine composition based on local surveillance. Analyses of influenza immunization effectiveness have neglected to account for the proportion of circulating viruses prevented from causing infection each year. We investigate this question for Madagascar, where influenza vaccines are not widely available.
METHODS
Seventy-eight Malagasy influenza strains characterized from 2002 to 2014 were challenged with hypothetical scenarios in which the WHO's Northern Hemisphere and Southern Hemisphere recommended vaccine compositions were provided to the population. Match between circulating and vaccine strains was determined by haemagglutination inhibition assays. Strain-specific positive matches were scored assuming 9 months of protection, and scenarios incorporated vaccine delays from zero to 5 months.
RESULTS
Malagasy influenza strains matched 54% and 44%, respectively, with the Northern Hemisphere and Southern Hemisphere recommended vaccine strains when the vaccine was delivered as soon as available. The matching values further decreased when additional delivery and application delays were considered. Differences between recommended compositions were not statistically significant.
CONCLUSION
Our results showed matching with the Northern Hemisphere vaccine barely above 50%, even in the more favourable scenario. This suggests that if implemented, routine influenza vaccines would not provide an optimal protection against half of the influenza strains circulating in any epidemic season of Madagascar. We suggest that this limitation in influenza vaccine efficacy deserves greater attention, and should be considered in cost/benefit analyses of national influenza immunization programmes.
背景
由于流感循环模式复杂，流感免疫接种在全球范围内仍然是一个严峻的挑战，尤其是在热带地区。热带地区应根据当地监测结果，选择世界卫生组织（WHO）推荐的北半球或南半球疫苗组合。流感免疫接种效果分析忽略了每年阻止循环病毒感染的比例。我们针对流感疫苗供应不足的马达加斯加进行了这项研究。
方法
从 2002 年到 2014 年，我们对 78 株马达加斯加流感病毒株进行了特征分析，并根据世界卫生组织推荐的北半球和南半球疫苗组合在假设情况下对其进行了挑战。通过血凝抑制试验确定循环病毒株与疫苗株之间的匹配情况。假设疫苗的保护期为 9 个月，对每种病毒株的特异性阳性匹配进行评分，并考虑了从零到 5 个月的疫苗接种延迟。
结果
当疫苗尽快供应时，马达加斯加流感株分别与北半球和南半球推荐的疫苗株的匹配率分别为 54%和 44%。当考虑到更多的交付和应用延迟时，匹配值进一步下降。推荐成分之间的差异没有统计学意义。
结论
我们的研究结果表明，即使在更有利的情况下，与北半球疫苗的匹配率也仅略高于 50%。这表明，如果实施常规流感疫苗，在马达加斯加的任何流感流行季节，疫苗都无法针对一半的流行病毒株提供最佳保护。我们建议，流感疫苗效力的这种局限性应引起更多关注，并应在国家流感免疫计划的成本效益分析中予以考虑。
Zotero 插件