Pediatrics. 2022 Nov 1;150(5). doi: 10.1542/peds.2022-057394.
On June 4, 2021, Italy launched the coronavirus disease 2019 (COVID-19) vaccination of adolescents to slow down the COVID-19 spread. Although clinical trials have evaluated messenger ribonucleic acid (mRNA) vaccine effectiveness in adolescents, there is limited literature on its real-world effectiveness. Accordingly, this study aimed to estimate the effectiveness of mRNA COVID-19 vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and mild or severe COVID-19 in a cohort of Sicilian adolescents within a 6 month observation period.
A retrospective cohort study was conducted with adolescents aged 12 to 18 years, residents of Sicily, who were followed from July 15 to December 31, 2021. SARS-CoV-2 infections, mild and severe COVID-19, and COVID-19-related intubation or deaths during the study period were compared between subjects vaccinated with 2 doses of mRNA vaccines and unvaccinated individuals. The Cox regression analysis, adjusted for age and sex, was performed to compare the 2 groups.
Overall, the study included a total at-risk population of 274 782 adolescents with 61.4% of them having completed the vaccination cycle by the end of the study. Unvaccinated subjects had higher incidence rates of SARS-CoV-2 (1043 × 10 000 vs 158.7 × 10 000 subjects), mild COVID-19 (27.7 × 10 000 vs 1.8 × 10 000 subjects) and severe COVID-19 (1.41 × 10 000 vs 0 subjects) compared with the vaccinated population. The estimated adjusted vaccine effectiveness against SARS-CoV-2 infection was 71.2%, reaching 92.1% and 97.9% against mild and severe COVID-19, respectively.
This study provides rigorous evidence of mRNA COVID-19 vaccines' effectiveness in protecting adolescents from both SARS-CoV-2 infection and COVID-19.
2021 年 6 月 4 日，意大利启动了针对青少年的 2019 年冠状病毒病（COVID-19）疫苗接种工作，以减缓 COVID-19 的传播。尽管临床试验已经评估了信使核糖核酸（mRNA）疫苗在青少年中的有效性，但关于其真实世界有效性的文献有限。因此，本研究旨在评估 mRNA COVID-19 疫苗在西西里岛青少年队列中预防严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）感染和轻度或重度 COVID-19 的有效性，观察期为 6 个月。
本研究采用回顾性队列研究设计，纳入了 2021 年 7 月 15 日至 12 月 31 日期间居住在西西里岛、年龄在 12 至 18 岁之间的青少年。比较了在研究期间接种 2 剂 mRNA 疫苗的受试者和未接种疫苗的个体之间 SARS-CoV-2 感染、轻度和重度 COVID-19 以及 COVID-19 相关的插管或死亡情况。采用 Cox 回归分析，调整年龄和性别因素，比较了两组人群。
总体而言，这项研究共纳入了 274782 名有风险的青少年人群，其中 61.4%的青少年在研究结束时完成了疫苗接种周期。与接种疫苗的人群相比，未接种疫苗的受试者 SARS-CoV-2 感染发生率更高（1043×10000 例比 158.7×10000 例）、轻度 COVID-19 发生率更高（27.7×10000 例比 1.8×10000 例）、重度 COVID-19 发生率更高（1.41×10000 例比 0 例）。mRNA COVID-19 疫苗预防 SARS-CoV-2 感染的估计调整疫苗有效性为 71.2%，对轻度和重度 COVID-19 的有效性分别达到 92.1%和 97.9%。
本研究为 mRNA COVID-19 疫苗在保护青少年免受 SARS-CoV-2 感染和 COVID-19 方面的有效性提供了严格的证据。
