Background: Influenza is a common respiratory infection at Hajj. Thus, influenza vaccine is recommended for Hajj pilgrims but data on its effectiveness from a large sample are unavailable. This analysis aims to assess the effectiveness of the trivalent seasonal influenza vaccine (TIV) among Hajj pilgrims.Patients and methods: A 'test-negative' case-control analysis using data from individual studies was conducted. Included studies involved participants from Saudi Arabia, India, Australia and the United Kingdom who attended Hajj in Makkah, Saudi Arabia in different years between 2005 and 2015. Pilgrims who developed symptoms of respiratory infection during Hajj were included in these studies. Participants' vaccination histories were recorded and respiratory samples were collected to test for influenza by PCR. Vaccine effectiveness (VE) was calculated after adjusting for potential confounders.Results: A total of 1,569 pilgrims were included in this analysis. Influenza vaccine uptake was 52.2% and the attack rate of influenza was 8.2%. The estimated overall VE was 43.4% (95% CI 11.4% to 63.9%, P = 0.01). VE against a specific subtype of influenza was not significant.Conclusion: The current analysis has shown that TIV is moderately effective among Hajj pilgrims, but the vaccine uptake has been suboptimal. Power was much reduced when testing for influenza subtypes.

中文翻译：

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朝Ha朝圣者中的流感疫苗效力：来自朝Ha不同年份的数据的试验阴性病例对照分析。

背景：流感是朝Ha的常见呼吸道感染。因此，朝圣朝圣者推荐使用流感疫苗，但尚无从大量样本中获得其有效性的数据。该分析旨在评估朝圣者三价季节性流感疫苗（TIV）的有效性。患者和方法：使用来自各个研究的数据进行了“试验阴性”病例对照分析。纳入的研究涉及来自沙特阿拉伯，印度，澳大利亚和英国的参与者，这些参与者于2005年至2015年间在沙特阿拉伯麦加朝圣。这些朝圣者在朝j期间出现呼吸道感染症状，被纳入这些研究。记录参与者的疫苗接种历史并收集呼吸道样本以通过PCR检测流感。校正潜在混杂因素后，计算出疫苗效力（VE）。结果：本次分析共包括1,569名朝圣者。流感疫苗的摄取率为52.2％，流感的发作率为8.2％。估计的总VE为43.4％（95％CI为11.4％至63.9％，P = 0.01）。结论：目前的分析表明，TIV在朝j朝圣者中中等有效，但对疫苗的吸收却不理想。测试流感亚型时，功率大大降低。结论：目前的分析表明，TIV在朝j朝圣者中中等有效，但对疫苗的吸收却不理想。测试流感亚型时，功率大大降低。结论：目前的分析表明，TIV在朝j朝圣者中中等有效，但对疫苗的吸收却不理想。测试流感亚型时，功率大大降低。