Choi Yu Jung, Song Joon Young, Wie Seong-Heon, Choi Won Suk, Lee Jacob, Lee Jin-Soo, Kim Young Keun, Kim Shin Woo, Lee Sun Hee, Park Kyung-Hwa, Jeong Hye Won, Yoon Jin Gu, Seong Hye, Nham Eliel, Noh Ji Yun, Cheong Hee Jin, Kim Woo Joo
Division of Infectious Diseases, Department of Internal Medicine, Guro Hospital, Korea University College of Medicine, Seoul, South Korea; Vaccine Innovation Center-KU Medicine (VIC-K), Seoul 02841, Republic of Korea.
Division of Infectious Diseases, Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, South Korea.
Vaccine. 2024 Dec 2;42(26):126381. doi: 10.1016/j.vaccine.2024.126381. Epub 2024 Oct 2.
Influenza imposes a significant healthcare burden in Korea, leading the government to initiate a national immunization program. Previous studies on vaccine effectiveness (VE) were limited to single-season estimation in Korea.
This multicenter prospective cohort study enrolled patients with influenza-like illnesses at 10 medical centers in Korea from 2011 to 2021. The demographic and clinical data were collected from questionnaire surveys and electronic medical records. Using a test-negative design, we aimed to investigate the effectiveness of a seasonal influenza vaccine for antigenic matching of the vaccine and circulating viral strains over 10 seasons.
Overall, 5322 adults aged ≥65 years were enrolled. Only three (33.3 %) of nine seasons showed >70 % antigenic match between vaccine and circulating strains. Influenza VE was significantly variable by season, ranging from -46.9 % (95 %confidence interval [CI]: -127.6-5.2) in the 2011/12 season to 47.7 % (95 %CI: 22.6-64.7) in the 2016/17 season. A significant difference was observed in the VE depending on whether the vaccine strains matched with epidemic strains: 28.8 % (95 %CI: 8.8-44.8) in matched seasons versus -12.0 % (95 %CI: -30.0-3.7) in mismatched seasons. Across the study period, influenza-related hospitalizations were reduced by 13.6 % (95 %CI: 0.7-24.8) with vaccination. In a subgroup analysis, the VE against influenza-related hospitalization was 48.4 % (95 %CI 29.6-62.2) in A/H3N2 dominant seasons and 53.8 % (95 %CI: -73.4-87.7) in A/H1N1 dominant seasons, respectively.
Influenza vaccine mismatch was frequent over the study period, leading to negligibly low VE in mismatched seasons. Influenza vaccination reduces the risk of influenza-related hospitalizations.
流感给韩国带来了沉重的医疗负担，促使政府启动了国家免疫计划。韩国此前关于疫苗效力（VE）的研究仅限于单季评估。
这项多中心前瞻性队列研究于2011年至2021年在韩国的10个医疗中心招募了流感样疾病患者。通过问卷调查和电子病历收集人口统计学和临床数据。采用检测阴性设计，我们旨在调查季节性流感疫苗在10个季节中针对疫苗与流行病毒株抗原匹配情况的效力。
总体而言，纳入了5322名年龄≥65岁的成年人。九个季节中只有三个季节（33.3%）显示疫苗与流行毒株之间的抗原匹配率>70%。流感疫苗效力随季节显著变化，从2011/12季节的-46.9%（95%置信区间[CI]：-127.6 - 5.2）到2016/17季节的47.7%（95%CI：22.6 - 64.7）。根据疫苗株是否与流行株匹配，观察到效力存在显著差异：匹配季节为28.8%（95%CI：8.8 - 44.8），不匹配季节为-12.0%（95%CI：-30.0 - 3.7）。在整个研究期间，接种疫苗使流感相关住院率降低了13.6%（95%CI：0.7 - 24.8）。在亚组分析中，在A/H3N2主导季节，针对流感相关住院的疫苗效力为48.4%（95%CI 29.6 - 62.2），在A/H1N1主导季节为53.8%（95%CI：-73.4 - 87.7）。
在研究期间，流感疫苗不匹配情况频繁发生，导致不匹配季节的疫苗效力低到可以忽略不计。接种流感疫苗可降低流感相关住院风险。
