Department of Pediatrics, Health Sciences Postgraduate Program, School of Medicine, Federal University of Minas Gerais (UFMG), R. Engenheiro Amaro Lanari 389/501, Belo Horizonte, MG, 30130-100, Brazil.
Department of Statistics, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
World J Pediatr. 2023 Oct;19(10):949-960. doi: 10.1007/s12519-023-00699-6. Epub 2023 Mar 13.
This study aimed to estimate vaccine effectiveness (VE) against omicron variant infection and severe corona virus disease 2019 (COVID-19) in children aged 5-11 years hospitalized with acute respiratory syndrome.
A test-negative, case-control analysis was conducted from February 2022 to June 2022. We enrolled 6950 eligible children, including 1102 cases and 5848 controls. VE was calculated after immunization with one and two doses of BNT162b2 or CoronaVac. The outcomes were hospitalization with acute respiratory symptoms and detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe COVID-19. The adjusted odds ratio for the association of prior vaccination and outcomes was used to estimate VE.
For fully vaccinated children, the overall estimated VE against hospitalization with SARS-CoV-2 infection was 42% [95% confidence interval (CI) 26 to 54]. VE peaked at 29-42 days (67%, 95% CI 40% to 82%) and then declined to 19% (95% CI, - 20% to 45%) at 57-120 days after the second dose. The BNT162b2 vaccine had a similar VE against hospitalization with SARS-CoV-2 infection (45%, 95% CI, 20 to 61) compared to the CoronaVac vaccine (40%, 95% CI, 17% to 56%). Among cases, 56 (5%) children died; 53 (94.6%) were not fully vaccinated. For cases, the two-dose schedule effectiveness against ICU admission, need for invasive ventilation, severe illness, and death were 10% (95% CI, - 54%-45%), 22% (95% CI - 70%-68%), 12% (95% CI, - 62%-52%), and 16% (95% CI, - 77%-75%), respectively.
For hospitalized children aged 5-11 years during the omicron-predominant period in Brazil, two doses of both vaccines had moderate effectiveness against hospitalization with acute respiratory symptoms and SARS-CoV-2 infection and offered limited protection against endpoints of COVID-19 severity.
本研究旨在评估针对 5-11 岁因急性呼吸道综合征住院的儿童的 omicron 变异感染和严重 2019 年冠状病毒病（COVID-19）的疫苗有效性（VE）。
从 2022 年 2 月至 2022 年 6 月进行了一项阴性测试、病例对照分析。我们招募了 6950 名符合条件的儿童，包括 1102 例病例和 5848 例对照。接种一剂和两剂 BNT162b2 或科兴疫苗后计算 VE。结果是因急性呼吸道症状住院和检测到严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）感染和严重 COVID-19。先前接种与结果相关的调整比值比用于估计 VE。
对于完全接种疫苗的儿童，针对 SARS-CoV-2 感染住院的总体估计 VE 为 42%（95%置信区间 26%至 54%）。VE 在接种后 29-42 天达到峰值（67%，95%CI 40%至 82%），然后在第二次接种后 57-120 天下降至 19%（95%CI，-20%至 45%）。与科兴疫苗相比，BNT162b2 疫苗对 SARS-CoV-2 感染的住院 VE 相似（45%，95%CI，20%至 61%）。在病例中，有 56 名（5%）儿童死亡；53 名（94.6%）未完全接种疫苗。对于病例，两剂方案对 ICU 入院、需要有创通气、严重疾病和死亡的有效性分别为 10%（95%CI，-54%-45%）、22%（95%CI-70%-68%）、12%（95%CI，-62%-52%）和 16%（95%CI，-77%-75%）。
在巴西 omicron 占主导地位的时期，5-11 岁因急性呼吸道综合征住院的儿童，两剂两种疫苗对因急性呼吸道症状和 SARS-CoV-2 感染住院具有中等效力，对 COVID-19 严重程度的终点提供有限的保护。
