GlaxoSmithKline Biologicals, Rixensart, Belgium.
BMC Pediatr. 2010 Feb 2;10:4. doi: 10.1186/1471-2431-10-4.
Introduction of the 7-valent pneumococcal conjugate vaccine (7vCRM) in several countries has led to a rapid, significant drop in vaccine-type invasive pneumococcal disease (IPD) in immunized children. In the United States and some other countries with high antibiotic use, a subsequent rise in serotype 19A IPD has been taken to indicate that the 19F conjugate in the vaccine provides no cross-protection against the immunologically related 19A.
We systematically assessed the clinical efficacy and effectiveness of 19F-containing vaccines against 19A disease or nasopharyngeal carriage by searching English-language articles in the electronic databases PubMed, Current contents, Scopus, and Embase from 1985 to 2008. The vaccine efficacy and effectiveness point estimates were consistently positive for modest protection against 19A IPD and acute otitis media (AOM). However, statistical significance was not reached in any individual study. No consistent impact of 7vCRM on 19A nasopharyngeal colonization could be detected. These findings are discussed in context of immunogenicity analyses indicating that 7vCRM induces functionally active anti-19A antibodies after the booster dose, and that other 19F-containing vaccine formulations may elicit higher levels of such antibodies after both primary and booster doses.
Taken together, these results suggest that 19F-conjugates can provide some protection against 19A disease. The magnitude of this protection in a given setting will likely depend on several factors. These include the anti-19A immunogenicity of the specific vaccine formulation, the number of doses of that formulation needed to elicit the response, and the burden of 19A disease that occurs after those doses. It is possible that a modest protective effect may be obscured by the presence of countervailing selection pressures (such as high antibiotic use) that favor an increase in colonization with antibiotic-non-susceptible strains of 19A.
在一些国家引入 7 价肺炎球菌结合疫苗（7vCRM）后，免疫儿童中疫苗型侵袭性肺炎球菌病（IPD）迅速显著下降。在美国和其他一些抗生素使用水平较高的国家，血清型 19A IPD 的后续上升表明疫苗中的 19F 结合物不能提供针对免疫相关的 19A 的交叉保护。
我们通过在 1985 年至 2008 年期间在电子数据库 PubMed、Current contents、Scopus 和 Embase 中搜索英文文章，系统地评估了含有 19F 的疫苗对 19A 疾病或鼻咽携带的临床疗效和效果。疫苗功效和效果的点估计值对于预防 19A IPD 和急性中耳炎（AOM）的适度保护均呈阳性。然而，在任何一项研究中均未达到统计学意义。未发现 7vCRM 对 19A 鼻咽定植的一致影响。这些发现与免疫原性分析的讨论一起表明，7vCRM 在加强剂量后诱导具有功能活性的抗 19A 抗体，并且其他含有 19F 的疫苗制剂在初次和加强剂量后可能产生更高水平的此类抗体。
总的来说，这些结果表明 19F 结合物可以提供对 19A 疾病的一定保护。在特定环境中，这种保护的程度可能取决于几个因素。这些因素包括特定疫苗制剂的抗 19A 免疫原性、引发反应所需的制剂剂量、以及在这些剂量后发生的 19A 疾病的负担。可能是由于存在抵消选择压力（例如抗生素的大量使用），有利于增加对具有抗生素耐药性的 19A 菌株的定植，从而掩盖了适度的保护作用。
