Nguyen Huong Q, Alonge Oluwakemi D, Hanson Kayla E, Stefanski Elisha, Petrie Joshua G, Ambrose Karita, Ghandhi Ashesh, Bissonnette Adam, Sylvester Gregg C, Meece Jennifer K, Belongia Edward A
Marshfield Clinic Research Institute, Marshfield, WI, United States.
CSL Seqirus, Summit, NJ, United States.
J Pediatric Infect Dis Soc. 2025 Jul 30. doi: 10.1093/jpids/piaf069.
The cell culture-based inactivated influenza vaccine (ccIIV) was first approved for use in children aged 4 through 17 years in 2016 in the United States. The approved age indication for ccIIV was expanded to include children 6 months and older beginning the 2022-2023 season. There is limited real-world data on ccIIV effectiveness in children. We assessed ccIIV effectiveness using the test-negative design during the 2023-2024 season.
Patients aged 6 months through 64 years who sought outpatient or telehealth care for acute respiratory illness were actively recruited between October 2023 and May 2024. Symptom eligibility criteria included cough with illness duration ≤7 days. Respiratory samples were tested by RT-PCR to identify influenza cases. Vaccination dates and products were determined by immunization records. Analyses were restricted to ccIIV recipients and unvaccinated participants. ccIIV effectiveness was estimated as [100% X (1 - odds ratio)] for vaccination in cases versus test-negative controls, with adjustment for age and calendar time.
Among 1850 participants, 12% were age 6 months through 3 years, 32% were age 4 through 17 years, and 56% were age 18 through 64 years. Influenza was detected in 505 (27%) participants; 267 had influenza A/H1N1pdm09, 149 had influenza B, 56 had influenza A/H3N2, and 33 had influenza A with unknown subtype. 470 (25%) received ccIIV. Among children (age 6 months through 17 years), ccIIV effectiveness was 64% [95% confidence interval (CI), 37%-81%] against influenza A/H1N1pdm09, 75% (95% CI, 43%-91%) against influenza B, and 76% (95% CI, 4%-97%) against influenza A/H3N2. Among adults (age 18 through 64 years), ccIIV effectiveness was 56% (95% CI, 31%-73%) against influenza A/H1N1pdm09, 62% (95% CI, 13%-86%) against influenza B, and 33% (95% CI, -62%-76%) against influenza A/H3N2. Young children aged 6 months through 3 years had the highest point estimates (88%-98%).
ccIIV generated substantial real-world effectiveness against medically attended, laboratory-confirmed influenza in children and adults during a season when influenza A/H1N1pdm09 viruses predominated and influenza B and influenza A/H3N2 co-circulated at lower levels.
基于细胞培养的灭活流感疫苗（ccIIV）于2016年在美国首次获批用于4至17岁儿童。从2022 - 2023年流感季开始，ccIIV的获批年龄范围扩大至6个月及以上儿童。关于ccIIV在儿童中的真实世界数据有限。我们在2023 - 2024年流感季使用检测阴性设计评估了ccIIV的有效性。
2023年10月至2024年5月期间，积极招募了因急性呼吸道疾病寻求门诊或远程医疗护理的6个月至64岁患者。症状入选标准包括咳嗽且病程≤7天。通过逆转录聚合酶链反应（RT-PCR）检测呼吸道样本以确定流感病例。通过免疫记录确定接种日期和疫苗产品。分析仅限于ccIIV接种者和未接种参与者。ccIIV的有效性通过病例组与检测阴性对照组接种疫苗的[100%×(1 - 比值比)]进行估计，并对年龄和日历时间进行调整。
在1850名参与者中，12%为6个月至3岁，32%为4至17岁，56%为18至64岁。505名（27%）参与者检测出流感；267人感染甲型H1N1pdm09流感，149人感染乙型流感，56人感染甲型H3N2流感，33人感染亚型不明的甲型流感。470名（25%）接受了ccIIV。在儿童（6个月至17岁）中，ccIIV对甲型H1N1pdm09流感的有效性为64%[95%置信区间（CI），37% - 81%]，对乙型流感为75%（95% CI，43% - 91%），对甲型H3N2流感为76%（95% CI，4% - 97%）。在成年人（18至64岁）中，ccIIV对甲型H1N1pdm09流感的有效性为56%（95% CI，31% - 73%），对乙型流感为62%（95% CI，13% - 86%），对甲型H3N2流感为33%（95% CI， - 62% - 76%）。6个月至3岁的幼儿有效性点估计值最高（88% - 98%）。
在甲型H1N1pdm09病毒占主导且乙型流感和甲型H3N2流感较低水平共同流行的流感季，ccIIV在预防儿童和成人因医疗就诊的实验室确诊流感方面产生了显著的真实世界有效性。
