Hammerton Savannah M, Billings W Zane, Hemme Hayley, Ross Ted M, Shen Ye, Handel Andreas
Department of Epidemiology and Biostatistics, College of Public Health.
Center for the Ecology of Infectious Diseases.
J Infect Dis. 2025 Jun 2;231(5):1336-1345. doi: 10.1093/infdis/jiae615.
The high-dose (HD) Fluzone influenza vaccine is recommended for individuals aged ≥65 years due to its improved antibody responses and vaccine efficacy (VE) over the standard-dose (SD) formulation. Since influenza vaccines are frequently reformulated, monitoring VE changes is crucial. Traditional efficacy trials are costly and time-consuming, but immunogenicity studies using hemagglutination inhibition (HAI) titers-a reliable correlate of protection-can be used to estimate VE more efficiently.
We analyzed data from a human vaccine cohort who received either the SD or HD Fluzone split-inactivated influenza vaccine during influenza seasons 2013-2014 to 2021-2022. We used a previously developed statistical model to map pre- and postvaccination HAI titers to protection probabilities, and computed differences in VE of the HD vaccine in older (≥65 years) populations compared to SD vaccines in the same age group and in younger (<65 years) adults.
We found that the HD vaccine generally improved the estimated VE in older adults. We also found that HD recipients often had a lower estimated VE than younger SD recipients.
While HD vaccines lead to a small increase in estimated VE compared to SD in older adults, further increases in dose or other developments to improve VE should be considered.
高剂量（HD）弗鲁赞流感疫苗因其相较于标准剂量（SD）配方具有更好的抗体反应和疫苗效力（VE），而被推荐用于65岁及以上的人群。由于流感疫苗经常重新配方，监测疫苗效力的变化至关重要。传统的效力试验成本高且耗时，但使用血凝抑制（HAI）滴度的免疫原性研究——一种可靠的保护相关性指标——可用于更有效地估计疫苗效力。
我们分析了一个人类疫苗队列的数据，该队列在2013 - 2014年至2021 - 2022年流感季节期间接种了SD或HD弗鲁赞裂解灭活流感疫苗。我们使用先前开发的统计模型将接种疫苗前后的HAI滴度映射到保护概率，并计算了老年（≥65岁）人群中HD疫苗与同年龄组SD疫苗以及年轻（<65岁）成年人中SD疫苗相比的疫苗效力差异。
我们发现HD疫苗总体上提高了老年人中估计的疫苗效力。我们还发现，HD疫苗接种者的估计疫苗效力通常低于年轻的SD疫苗接种者。
虽然与SD疫苗相比，HD疫苗在老年人中使估计的疫苗效力略有增加，但应考虑进一步增加剂量或进行其他改进疫苗效力的研发。
