Kahn Sagol Maccabi Research & Innovation Center, Maccabi Healthcare Services, Tel Aviv, Israel; Maccabitech Institute for Research and Innovation, Maccabi Healthcare Services, Tel Aviv, Israel.
Kahn Sagol Maccabi Research & Innovation Center, Maccabi Healthcare Services, Tel Aviv, Israel.
J Pediatr. 2023 Jun;257:113371. doi: 10.1016/j.jpeds.2023.02.016. Epub 2023 Mar 3.
To evaluate the duration of protection against reinfection conferred by a previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children and adolescents.
We applied 2 complementary approaches: a matched test-negative, case-control design and a retrospective cohort design. A total of 458 959 unvaccinated individuals aged 5-18 years were included. The analyses focused on the period July 1, 2021, to December 13, 2021, a period of Delta variant dominance in Israel. We evaluated 3 SARS-CoV-2-related outcomes: documented polymerase chain reaction-confirmed infection or reinfection, symptomatic infection or reinfection, and SARS-CoV-2-related hospitalization or death.
Overall, children and adolescents who were previously infected acquired durable protection against reinfection with SARS-CoV-2 for at least 18 months. Importantly, no SARS-CoV-2-related deaths were recorded in either the SARS-CoV-2-naïve group or the previously infected group. The effectiveness of naturally acquired immunity against a recurrent infection reached 89.2% (95% CI, 84.7%-92.4%) at 3-6 months after the first infection and declined slightly to 82.5% (95% CI, 79.1%-85.3%) by 9-12 months after infection, with a slight nonsignificant waning trend seen up to 18 months after infection. Additionally, children aged 5-11 years exhibited no significant waning of naturally acquired protection throughout the outcome period, whereas waning protection in those aged 12-18 years was more prominent but still mild.
Children and adolescents who were previously infected with SARS-CoV-2 remain protected to a high degree for 18 months. Further research is needed to examine naturally acquired immunity against Omicron and newer emerging variants.
评估既往严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）感染对儿童和青少年再次感染的保护持续时间。
我们应用了 2 种互补方法：匹配的病例对照研究和回顾性队列研究。共纳入了 458959 名未接种疫苗的 5-18 岁个体。分析集中在 2021 年 7 月 1 日至 2021 年 12 月 13 日期间，这一时期以色列以 Delta 变异株为主导。我们评估了 3 种与 SARS-CoV-2 相关的结局：有记录的聚合酶链反应确诊感染或再感染、有症状的感染或再感染以及 SARS-CoV-2 相关住院或死亡。
总体而言，既往感染过 SARS-CoV-2 的儿童和青少年对 SARS-CoV-2 获得了至少 18 个月的持久保护，防止再次感染。重要的是，在 SARS-CoV-2 未感染组或既往感染组均未记录到 SARS-CoV-2 相关死亡。自然获得的免疫力对再次感染的有效性在首次感染后 3-6 个月达到 89.2%（95%CI，84.7%-92.4%），并在感染后 9-12 个月略有下降至 82.5%（95%CI，79.1%-85.3%），感染后 18 个月仍呈轻微的非显著衰减趋势。此外，5-11 岁儿童在整个结局期间未表现出自然获得的保护作用显著衰减，而 12-18 岁儿童的保护作用衰减更明显，但仍较为温和。
既往感染过 SARS-CoV-2 的儿童和青少年在 18 个月内仍受到高度保护。需要进一步研究来检测针对 Omicron 和新出现变异株的自然获得免疫力。
