Vu Trang Thu, Ngo Tu Huy, Nguyen Khanh Cong, Lan Vu Thi, Hanh Cu Thi Bich, Son Le Hong, Nguyen Huyen Thi, Nguyen Hien Thi, Ngu Nghia Duy, Tran Duong Nhu, Dang Duc-Anh, Vogt Florian, Pham Thai Quang
National Centre for Epidemiology and Population Health, College of Health and Medicine, Australian National University, Canberra, Australian Capital Territory, Australia.
Department of Communicable Disease Control and Prevention, National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam.
Western Pac Surveill Response J. 2024 Jul 11;15(3):1-12. doi: 10.5365/wpsar.2024.15.3.1077. eCollection 2024 Apr-Jun.
The risk of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from schoolchildren to their household and the protective effects of vaccination in these settings remain poorly understood. We assessed the transmission dynamics of schoolchildren with SARS-CoV-2 within their households and the protective effects of coronavirus disease (COVID-19) vaccination among household members in Viet Nam.
We estimated the attack rate, vaccine effectiveness and adjusted risk ratio (aRR) of factors associated with SARS-CoV-2 transmission to household contacts of children confirmed to have COVID-19 who attended three schools in Ha Nam, Phu Tho and Thanh Hoa provinces between September and December 2021 using multivariable regression with household-level random effects.
This retrospective cohort study included 157 children infected with SARS-CoV-2 and their 540 household contacts. The attack rate among household contacts was 24.6% (133/540). Overall, vaccine effectiveness among household contacts was 39% (95% confidence interval [CI]: -1 to -63), higher among males than females and higher in adults aged > 40 years. COVID-19 transmission was greater among female household contacts compared with males (aRR: 1.35, 95% CI: 0.94 to 1.95), although not statistically significant, and highest among those aged 19-39 years (aRR: 2.51, 95% CI: 1.50 to 4.21). Fully vaccinated household contacts had significantly lower infection risk (aRR: 0.46, 95% CI: 0.26 to 0.84).
We found substantial onward transmission of SARS-CoV-2 from schoolchildren to household members, and older people were more likely to be protected by vaccination. We recommend that schoolchildren and all household members living with schoolchildren receive at least two doses of a COVID-19 vaccine. Recognizing the role of schoolchildren in the onward transmission of COVID-19 is an important lesson learned by Viet Nam that can help not only in managing other outbreaks but also in protecting schoolchildren by predicting the progress of the outbreak and preparing for a timely response.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）从学童传播至其家庭成员的风险以及疫苗接种在此类情况下的保护作用仍未得到充分了解。我们评估了越南学童感染SARS-CoV-2后在其家庭内的传播动态以及家庭成员中冠状病毒病（COVID-19）疫苗接种的保护作用。
我们估计了2021年9月至12月期间在河南、富寿和清化三省三所学校就读且确诊感染COVID-19的儿童的家庭接触者感染SARS-CoV-2的发病率、疫苗效力和调整风险比（aRR），采用具有家庭水平随机效应的多变量回归分析。
这项回顾性队列研究纳入了157名感染SARS-CoV-2的儿童及其540名家庭接触者。家庭接触者中的发病率为24.6%（133/540）。总体而言，家庭接触者中的疫苗效力为39%（95%置信区间[CI]：-1至-63），男性高于女性，40岁以上成年人更高。与男性相比，女性家庭接触者中的COVID-19传播率更高（aRR：1.35，95%CI：0.94至1.95），尽管无统计学意义，且在19-39岁人群中最高（aRR：2.51，95%CI：1.50至4.21）。完全接种疫苗的家庭接触者感染风险显著更低（aRR：0.46，95%CI：0.26至0.84）。
我们发现SARS-CoV-2从学童大量传播至家庭成员，且老年人更有可能通过接种疫苗得到保护。我们建议学童以及与学童共同生活的所有家庭成员接种至少两剂COVID-19疫苗。认识到学童在COVID-19传播中的作用是越南汲取的重要经验教训，这不仅有助于应对其他疫情暴发，还能通过预测疫情进展并做好及时应对准备来保护学童。
