Vaccine Effectiveness Against Long COVID in Children: A Report from the RECOVER EHR Cohort

Objective Vaccination reduces the risk of acute COVID-19 in children, but it is less clear whether it protects against long COVID. We estimated vaccine effectiveness (VE) against long COVID in children aged 5 to 17 years. Methods This retrospective cohort study used data from 17 health systems in the RECOVER PCORnet electronic health record (EHR) Program for visits between vaccine availability, and October 29, 2022. Conditional logistic regression was used to estimate VE against long COVID with matching on age group (5 to 11, 12 to 17) and time period and adjustment for sex, ethnicity, health system, comorbidity burden, and pre-exposure health care utilization. We examined both probable (symptom-based) and diagnosed long COVID in the year following vaccination. Results The vaccination rate was 56% in the cohort of 1,037,936 children. The incidence of probably long COVID was 4.5% among patients with COVID-19, while diagnosed long COVID was 0.7%. Adjusted vaccine effectiveness within 12 months was 35.4% (95 CI 24.5 - 44.5) against probable long COVID and 41.7% (15.0- 60.0) against diagnosed long COVID. VE was higher for adolescents 50.3% [36.3 - 61.0]) than children aged 5-11 (23.8% [4.9 -39.0]). VE was higher at 6 months (61.4% [51.0 - 69.6]), but decreased to 10.6% (-26.8 - 37.0%) at 18 months. Discussion This large retrospective study shows a moderate protective effect of SARS-CoV-2 vaccination against long COVID. The effect is stronger in adolescents, who have higher risk of long COVID, and wanes over time. Understanding VE mechanism against long COVID requires more study, including EHR sources and prospective data. Discussion This large retrospective study shows a moderate protective effect of SARS-CoV-2 vaccination against long COVID. The effect is stronger in adolescents, who have higher risk of long COVID, and wanes over time. Understanding VE mechanism against long COVID requires more study, including EHR sources and prospective data.

目的 疫苗接种可降低儿童患急性新冠的风险，但对于其是否能预防新冠长期症状尚不明确。我们估算了5至17岁儿童中疫苗对新冠长期症状的有效性（VE）。 方法 这项回顾性队列研究使用了RECOVER PCORnet电子健康记录（EHR）项目中17个医疗系统的数据，时间跨度为疫苗可获得至2022年10月29日期间的就诊记录。采用条件逻辑回归来估算对新冠长期症状的疫苗有效性，按年龄组（5至11岁、12至17岁）和时间段进行匹配，并对性别、种族、医疗系统、合并症负担以及暴露前医疗保健利用情况进行调整。我们研究了接种疫苗后一年内可能的（基于症状）和确诊的新冠长期症状。 结果 在1037936名儿童队列中，疫苗接种率为56%。在新冠患者中，可能的新冠长期症状发生率为4.5%，而确诊的新冠长期症状发生率为0.7%。在12个月内，调整后的疫苗对可能的新冠长期症状的有效性为35.4%（95%置信区间24.5 - 44.5），对确诊的新冠长期症状的有效性为41.7%（15.0 - 60.0）。青少年的疫苗有效性（50.3%[36.3 - 61.0]）高于5 - 11岁儿童（23.8%[4.9 - 39.0]）。在6个月时疫苗有效性较高（61.4%[51.0 - 69.6]），但在18个月时降至10.6%（-26.8 - 37.0%）。 讨论 这项大型回顾性研究表明，新冠疫苗接种对新冠长期症状有适度的保护作用。这种作用在青少年中更强，他们患新冠长期症状的风险更高，且随着时间推移而减弱。了解针对新冠长期症状的疫苗有效性机制需要更多研究，包括电子健康记录来源和前瞻性数据。