OBJECTIVES The quadrivalent influenza vaccine (QIV) contains two influenza B antigens (one of each B lineage), while the trivalent vaccine (TIV) contains solely one. As a result, a mismatch between the circulating B lineage and the lineage in the TIV occurs frequently. We aimed to compare the frequency of clinically significant outcomes in a large cohort of vaccinees receiving either TIV or QIV. METHODS Historical cohort study of all inactivated influenza vaccinees (aged 3 years and older) in a Health Maintenance Organization insuring 1.2 million individuals, over two influenza seasons in which both vaccines were provided non-selectively. Primary outcome was hospital admissions during the influenza season. Multivariate analysis was performed using logistic regression to adjust for relevant covariates. RESULTS Our cohort included 150 518 and 168 296 vaccinees in the first (S1) and second season (S2), respectively. The two influenza seasons were characterized by high Influenza B activity. Of those vaccinated with QIV, 2074 of 49 726 (4.2%) and 6563 of 121 741 (5.4%) were hospitalized compared with 7378 of 100 792 (7.3%) and 3372 of 46 555 (7.2%) of those vaccinated with TIV (S1 and S2, respectively). After multivariate analysis adjusting for several covariates (gender, age, socioeconomic status, chronic morbidity, timing of vaccination), compared with TIV recipients, QIV vaccinees had lower odds for hospitalization (OR = 0.92, 95% CI 0.87-0.98 and OR = 0.89, 95% CI 0.85-0.93) or emergency department visit (OR = 0.91, 95% CI 0.87-0.95 and OR = 0.84, 95% CI 0.81-0.87) in S1 and S2, respectively (p < 0.001). Lower odds of mortality and influenza-like illness were also observed in S2 (OR = 0.61, 95% CI 0.50-0.75 and OR = 0.92, 95% CI 0.90-0.95, respectively). CONCLUSIONS In seasons with relatively high influenza B activity, QIV appeared more protective than TIV in Israel.

中文翻译：

---

四价与三价流感疫苗：两个流感季节的临床结果，历史队列研究。

目的四价流感疫苗（QIV）包含两种B型流感抗原（每个B谱系之一），而三价疫苗（TIV）仅包含一种。结果，循环的B谱系和TIV中的谱系之间经常发生不匹配。我们的目的是比较在接受TIV或QIV的大量疫苗接种中具有临床意义的结果发生的频率。方法在健康维持组织中，所有两个灭活的流感疫苗（3岁及以上）的历史队列研究确保了在两个流感季节中非选择性提供两种疫苗的120万个体的保险。主要结局是在流感季节住院。使用逻辑回归进行多变量分析以调整相关协变量。结果我们的队列在第一季（S1）和第二季（S2）分别包括150 518和168 296疫苗。这两个流感季节的特征是乙型流感活动活跃。在接受QIV疫苗接种的人中，有2074例（49 726）（4.2％）和6563（121％741）（5.4％）在医院，相比之下，在TIV疫苗中的7378（100 792（7.3％））和3372（46 555）（7.2％）（ S1和S2）。在对多个协变量（性别，年龄，社会经济状况，慢性病，疫苗接种时间）进行多因素分析调整后，与TIV接受者相比，QIV疫苗的住院几率更低（OR = 0.92、95％CI 0.87-0.98和OR = 0.89 ，S1和S2中分别为95％CI 0.85-0.93）或急诊就诊（OR = 0.91、95％CI 0.87-0.95和OR = 0.84、95％CI 0.81-0.87）（p <0.001）。在S2中也观察到死亡率和流感样疾病的几率较低（分别为OR = 0.61，95％CI 0.50-0.75和OR = 0.92，95％CI 0.90-0.95）。结论在乙型流感活动相对较高的季节中，以色列的QIV比TIV更具保护性。