Armed Forces Health Surveillance Center, Silver Spring, Maryland, United States of America.
PLoS One. 2012;7(7):e41435. doi: 10.1371/journal.pone.0041435. Epub 2012 Jul 31.
Following the 2009 influenza A/H1N1 (pH1N1) pandemic, both seasonal and pH1N1 viruses circulated in the US during the 2010-2011 influenza season; influenza vaccine effectiveness (VE) may vary between live attenuated (LAIV) and trivalent inactivated (TIV) vaccines as well as by virus subtype.
Vaccine type and virus subtype-specific VE were determined for US military active component personnel for the period of September 1, 2010 through April 30, 2011. Laboratory-confirmed influenza-related medical encounters were compared to matched individuals with a non-respiratory illness (healthy controls), and unmatched individuals who experienced a non-influenza respiratory illness (test-negative controls). Odds ratios (OR) and VE estimates were calculated overall, by vaccine type and influenza subtype.
A total of 603 influenza cases were identified. Overall VE was relatively low and similar regardless of whether healthy controls (VE = 26%, 95% CI: -1 to 45) or test-negative controls (VE = 29%, 95% CI: -6 to 53) were used as comparison groups. Using test-negative controls, vaccine type-specific VE was found to be higher for TIV (53%, 95% CI: 25 to 71) than for LAIV (VE = -13%, 95% CI: -77 to 27). Influenza subtype-specific analyses revealed moderate protection against A/H3 (VE = 58%, 95% CI: 21 to 78), but not against A/H1 (VE = -38%, 95% CI: -211 to 39) or B (VE = 34%, 95% CI: -122 to 80).
Overall, a low level of protection against clinically-apparent, laboratory-confirmed, influenza was found for the 2010-11 seasonal influenza vaccines. TIV immunization was associated with higher protection than LAIV, however, no protection against A/H1 was noted, despite inclusion of a pandemic influenza strain as a vaccine component for two consecutive years. Vaccine virus mismatch or lower immunogenicity may have contributed to these findings and deserve further examination in controlled studies. Continued assessment of VE in military personnel is essential in order to better inform vaccination policy decisions.
在 2009 年甲型 H1N1（pH1N1）流感大流行之后，季节性流感病毒和 pH1N1 病毒在 2010-2011 年流感季节在美国同时流行；流感疫苗的有效性（VE）可能因活减毒疫苗（LAIV）和三价灭活疫苗（TIV）以及病毒亚型的不同而有所差异。
本研究针对 2010 年 9 月 1 日至 2011 年 4 月 30 日期间美国军队现役人员，确定了疫苗类型和病毒亚型特异性 VE。通过实验室确认的流感相关医疗接触与匹配的非呼吸道疾病个体（健康对照）和经历非流感呼吸道疾病的非匹配个体（阴性对照）进行比较。总体以及按疫苗类型和流感亚型计算比值比（OR）和 VE 估计值。
共确定了 603 例流感病例。无论使用健康对照（VE=26%，95%CI：-1 至 45）还是阴性对照（VE=29%，95%CI：-6 至 53）作为对照组，总体 VE 均相对较低且相似。使用阴性对照，TIV 的疫苗类型特异性 VE 较高（VE=53%，95%CI：25 至 71），而 LAIV 的 VE 较低（VE=-13%，95%CI：-77 至 27）。流感亚型特异性分析显示，对 A/H3 有中等程度的保护作用（VE=58%，95%CI：21 至 78），但对 A/H1（VE=-38%，95%CI：-211 至 39）或 B（VE=34%，95%CI：-122 至 80）无保护作用。
总的来说，2010-11 年季节性流感疫苗对临床明显、实验室确诊的流感的保护水平较低。TIV 免疫接种与 LAIV 相比具有更高的保护作用，但对 A/H1 没有保护作用，尽管连续两年都将一种大流行流感株作为疫苗成分。疫苗病毒不匹配或免疫原性较低可能导致了这些发现，值得在对照研究中进一步研究。继续评估军事人员的 VE 对于更好地为疫苗接种决策提供信息至关重要。
