Division of Geriatrics and Palliative Care, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA.
Center on Innovation in Long-Term Services and Supports, Veterans Administration Medical Center, Providence, Rhode Island, USA.
Clin Infect Dis. 2021 Dec 6;73(11):e4229-e4236. doi: 10.1093/cid/ciaa1916.
Influenza outbreaks in nursing homes pose a threat to frail residents and occur even in vaccinated populations. We conducted a pragmatic cluster-randomized trial comparing adjuvanted trivalent influenza vaccine (aTIV) versus trivalent influenza vaccine (TIV). We report an exploratory analysis to compare the effect of aTIV versus TIV on facility-reported influenza outbreaks.
We evaluated the impact of the intent-to-treat vaccine assignment on outbreaks reported from November 2016 to March 2017. We collected data according to standard CDC definitions for both suspected outbreaks and those with a laboratory-confirmed case and adjusted for facility-level vaccination rates and resident characteristics in nursing homes.
Of 823 randomized nursing homes, 777 (aTIV, n = 387; TIV, n = 390) reported information on influenza outbreaks. Treatment groups had similar characteristics at baseline except for race/ethnicity: homes assigned to TIV had a higher percentage of African-American residents (18.0% vs 13.7%). There were 133 versus 162 facility-reported suspected influenza outbreaks in aTIV versus TIV facilities, respectively; of these, 115 versus 140 were laboratory confirmed. The aTIV group experienced a 17% reduction in suspected (rate ratio, .83; 95% confidence interval, .65-1.05) and laboratory-confirmed (.83; .63-1.06) influenza outbreaks. Covariate adjustment increased the estimated reduction for suspected outbreaks to 21% (.79; .61-.99) and 22% for laboratory-confirmed outbreaks (.78; .60-1.02).
In an exploratory analysis of a cluster-randomized trial we observed 17-21% fewer outbreaks with aTIV than TIV. Clinical Trials Registration. (NCT02882100).
养老院中的流感爆发对体弱的居民构成威胁，即使在接种疫苗的人群中也会发生。我们进行了一项实用的群组随机试验，比较了含佐剂的三价流感疫苗（aTIV）与三价流感疫苗（TIV）。我们报告了一项探索性分析，比较 aTIV 与 TIV 对机构报告的流感爆发的影响。
我们评估了意向治疗疫苗分配对 2016 年 11 月至 2017 年 3 月报告的爆发的影响。我们根据疾病预防控制中心对疑似爆发和实验室确诊病例的标准定义收集数据，并根据养老院的设施级疫苗接种率和居民特征进行了调整。
在 823 家随机分配的养老院中，有 777 家（aTIV，n = 387；TIV，n = 390）报告了流感爆发信息。治疗组在基线时具有相似的特征，除了种族/民族：TIV 组的非裔美国人居民比例较高（18.0% vs 13.7%）。aTIV 组和 TIV 组分别有 133 例和 162 例机构报告的疑似流感爆发；其中 115 例和 140 例为实验室确诊。aTIV 组疑似（发病率比，0.83；95%置信区间，0.65-1.05）和实验室确诊（发病率比，0.83；0.63-1.06）流感爆发的发生率降低了 17%。调整协变量后，疑似爆发的估计减少率增加到 21%（0.79；0.61-0.99），实验室确诊的爆发减少率增加到 22%（0.78；0.60-1.02）。
在一项群组随机试验的探索性分析中，我们观察到 aTIV 组的爆发比 TIV 组减少了 17%-21%。临床试验注册（NCT02882100）。
