Influenza Vaccination for Immunocompromised Patients: Systematic Review and Meta-Analysis from a Public Health Policy Perspective

BackgroundImmunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events. Methodology/Principal FindingsElectronic databases and grey literature were searched and records were screened against eligibility criteria. Data extraction and risk of bias assessments were performed in duplicate. Results were synthesised narratively and meta-analyses were conducted where feasible. Heterogeneity was assessed using I2 and publication bias was assessed using Begg's funnel plot and Egger's regression test. Many of the 209 eligible studies included an unclear or high risk of bias. Meta-analyses showed a significant effect of preventing influenza-like illness (odds ratio [OR] = 0.23; 95% confidence interval [CI] = 0.16–0.34; p Conclusions/SignificanceInfection prevention and control strategies should recommend vaccinating immunocompromised patients. Potential for bias and confounding and the presence of heterogeneity mean the evidence reviewed is generally weak, although the directions of effects are consistent. Areas for further research are identified.

背景：免疫功能低下患者易罹患重症或复杂性流感感染，接种疫苗是该人群的广泛推荐预防措施。本系统评价与荟萃分析针对免疫功能低下患者的流感疫苗接种，从预防流感样疾病、实验室确诊流感、血清学应答及不良事件四个维度展开评估。
研究方法与主要结果：通过电子数据库与灰色文献开展文献检索，并依据纳入排除标准筛选文献记录；采用双人独立模式完成数据提取与偏倚风险评估；结果以叙述性综合方式呈现，可行情况下开展荟萃分析；异质性检验采用I²统计量，发表偏倚则通过Begg漏斗图（Begg's funnel plot）与Egger回归检验（Egger's regression test）进行评估。本研究纳入的209项合格研究中，多数存在偏倚风险不明或高偏倚风险的情况。荟萃分析结果显示，疫苗在预防流感样疾病方面具有显著效果（比值比[odds ratio, OR] = 0.23；95%置信区间[confidence interval, CI] = 0.16–0.34；P < 0.001）。
结论与意义：感染防控策略应推荐为免疫功能低下患者接种流感疫苗。尽管研究所得效应方向一致，但现有纳入研究存在偏倚、混杂因素以及异质性，使得本综述所依据的证据整体强度较弱。本研究同时明确了未来有待开展的研究方向。