Genetics, Vaccines and Pediatric Infectious Diseases Research Group (GENVIP), Instituto de Investigación Sanitaria de Santiago (IDIS), Santiago de Compostela, Galicia, Spain.
WHO Collaborating Centre for Vaccine Safety, Santiago de Compostela, Spain.
Pediatr Allergy Immunol. 2023 Oct;34(10):e14037. doi: 10.1111/pai.14037.
Studies on vaccine effectiveness (VE) against COVID-19 in the pediatric population are outgoing. We aimed to quantify VE against SARS-CoV-2 in two pediatric age groups, 5-11 and 12-17-year-old, while considering vaccine type, SARS-CoV-2 variant, and duration of protection.
A population-based test-negative control study was undertaken in Galicia, Spain. Children 5-11-year-old received the Comirnaty® (Pfizer, US) vaccine, while those aged 12-17-year-old received the Comirnaty® (Pfizer, US) or SpikeVax® (ModernaTX, Inc) vaccine. Participants were categorized into unvaccinated (0 doses or one dose with <14 days since vaccination), partially vaccinated (only one dose with ≥14 days, or two doses with <14 days after the second dose administration), and fully vaccinated (two doses with ≥14 days after the second injection). Adjusted odds ratios (OR) and their 95% confidence intervals (CI) were estimated using multiple logistic regression models. VE was calculated as (1-OR) * 100. Stratified and sensitivity analyses were performed.
In the fully vaccinated 5-11-year-old children, VE against the Omicron variant was 44.1% (95% CI: 38.2%-49.4%). In the fully vaccinated 12-17-year-old individuals, VE was 83.4% (95% CI: 81.2%-85.3%) against Delta and 74.8% (95% CI: 58.5%-84.9%) against Omicron. Comirnaty® and SpikeVax® vaccines showed a similar magnitude of VE against Delta [Comirnaty® VE: 81.9% (95% CI: 79.3%-84.1%) and SpikeVax® VE: 85.3% (95% CI: 81.9%-88.1%)]. Comirnaty® (Pfizer, US; VE: 79.7%; 95% CI: 50.7%-92.4%) showed a slightly higher magnitude of protection against Omicron than SpikeVax® (ModernaTX, Inc), yet with an overlapping CI (VE: 74.3%; 95% CI: 56.6%-84.9%). VE was maintained in all age subgroups in both pediatric populations, but it declined over time.
In Galicia, mRNA VE was moderate against SARS-CoV-2 infections in the 5-11-year-old populations, but high in older children. VE declined over time, suggesting a potential need for booster dose schedules.
针对儿童人群 COVID-19 疫苗效力（VE）的研究较少。我们旨在量化两种儿科年龄组（5-11 岁和 12-17 岁）中，针对 SARS-CoV-2 的 VE，同时考虑疫苗类型、SARS-CoV-2 变异株和保护持续时间。
在西班牙加利西亚开展了一项基于人群的病例对照研究。5-11 岁儿童接种 Comirnaty®（辉瑞，美国）疫苗，12-17 岁儿童接种 Comirnaty®（辉瑞，美国）或 SpikeVax®（ModernaTX，美国）疫苗。参与者分为未接种组（0 剂或接种 1 剂且距接种后<14 天）、部分接种组（仅接种 1 剂且距接种后≥14 天，或接种第 2 剂后<14 天接种 2 剂）和完全接种组（接种 2 剂且距接种第 2 剂后≥14 天）。使用多因素逻辑回归模型估计调整后的比值比（OR）及其 95%置信区间（CI）。VE 计算为（1-OR）*100。进行了分层和敏感性分析。
在完全接种的 5-11 岁儿童中，针对奥密克戎变异株的 VE 为 44.1%（95%CI：38.2%-49.4%）。在完全接种的 12-17 岁人群中，针对 Delta 的 VE 为 83.4%（95%CI：81.2%-85.3%），针对奥密克戎的 VE 为 74.8%（95%CI：58.5%-84.9%）。Comirnaty®和 SpikeVax®疫苗对 Delta 的 VE 相似[Comirnaty®VE：81.9%（95%CI：79.3%-84.1%）和 SpikeVax®VE：85.3%（95%CI：81.9%-88.1%）]。Comirnaty®（辉瑞，美国；VE：79.7%；95%CI：50.7%-92.4%）对奥密克戎的保护作用略高于 SpikeVax®（ModernaTX，美国），但 CI 重叠（VE：74.3%；95%CI：56.6%-84.9%）。在两个儿科人群中，VE 在所有年龄亚组中均保持稳定，但随时间推移而下降。
在加利西亚，mRNA 在 5-11 岁儿童人群中对 SARS-CoV-2 感染的 VE 适中，但在较大儿童中较高。VE 随时间下降，提示可能需要加强免疫接种方案。
