Kubale John, Balmaseda Angel, Frutos Aaron M, Sanchez Nery, Plazaola Miguel, Ojeda Sergio, Saborio Saira, Lopez Roger, Barilla Carlos, Vasquez Gerald, Moreira Hanny, Gajewski Anna, Campredon Lora, Maier Hannah, Chowdhury Mahboob, Cerpas Cristhiam, Harris Eva, Kuan Guillermina, Gordon Aubree
Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA.
Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua.
medRxiv. 2022 Jan 5:2022.01.03.22268684. doi: 10.1101/2022.01.03.22268684.
The impact of the SARS-CoV-2 pandemic on children remains unclear. Better understanding of the burden of COVID-19 among children and their protection against re-infection is crucial as they will be among the last groups vaccinated.
To characterize the burden of COVID-19 and assess how protection from symptomatic re-infection among children may vary by age.
A prospective, community-based pediatric cohort study conducted from March 1, 2020 through October 15, 2021.
The Nicaraguan Pediatric Influenza Cohort is a community-based cohort in District 2 of Managua, Nicaragua.
A total of 1964 children aged 0-14 years participated in the cohort. Non-immunocompromised children were enrolled by random selection from a previous pediatric influenza cohort. Additional newborn infants aged ≤4 weeks were randomly selected and enrolled monthly, via home visits.
Prior COVID-19 infection as confirmed by positive anti SARS-CoV-2 antibodies (receptor binding domain [RBD] and spike protein) or real time RT-PCR confirmed COVID-19 infection ≥60 days prior to current COVID-19.
Symptomatic COVID-19 cases confirmed by real time RT-PCR and hospitalization within 28 days of symptom onset of confirmed COVID-19 case.
Overall, 49.8% of children tested were seropositive over the course of the study. There were also 207 PCR-confirmed COVID-19 cases, 12 (6.4%) of which were severe enough to require hospitalization. Incidence of COVID-19 was highest among children aged <2 years-16.1 per 100 person-years (95% Confidence Interval [CI]: 12.5, 20.5)-approximately three times that of children in any other age group assessed. Additionally, 41 (19.8%) symptomatic SARS-CoV-2 episodes were re-infections, with younger children slightly more protected against symptomatic reinfection. Among children aged 6-59 months, protection was 61% (Rate Ratio [RR]:0.39, 95% CI:0.2,0.8), while protection among children aged 5-9 and 10-14 years was 64% (RR:0.36,0.2,0.7), and 49% (RR:0.51,0.3-0.9), respectively.
In this prospective community-based pediatric cohort rates of symptomatic and severe COVID-19 were highest among the youngest participants, with rates stabilizing around age 5. Reinfections represent a large proportion of PCR-positive cases, with children <10 years displaying greater protection from symptomatic reinfection. A vaccine for children <5 years is urgently needed.
What is the burden of COVID-19 among young children and how does protection from re-infection vary with age? In this study of 1964 children aged 0-14 years children <5 years had the highest rates of symptomatic and severe COVID-19 while also displaying greater protection against re-infection compared to children ≥10 years. Given their greater risk of infection and severe disease compared to older children, effective vaccines against COVID-19 are urgently needed for children under 5.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）大流行对儿童的影响仍不明确。更好地了解儿童中冠状病毒病（COVID-19）的负担以及他们预防再次感染的情况至关重要，因为他们将是最后一批接种疫苗的人群之一。
描述COVID-19的负担，并评估儿童中症状性再次感染的防护情况如何随年龄而变化。
一项前瞻性、基于社区的儿科队列研究，于2020年3月1日至2021年10月15日进行。
尼加拉瓜儿科流感队列是尼加拉瓜马那瓜第二区的一个基于社区的队列。
共有1964名0至14岁的儿童参与了该队列。非免疫功能低下的儿童是从先前的儿科流感队列中随机选择纳入的。另外，每月通过家访随机选择并纳入年龄≤4周的新生儿。
通过抗SARS-CoV-2抗体（受体结合域[RBD]和刺突蛋白）阳性或实时逆转录聚合酶链反应（RT-PCR）确认在当前COVID-19感染前≥60天曾感染过COVID-19。
通过实时RT-PCR确认的症状性COVID-19病例以及确诊COVID-19病例症状出现后28天内的住院情况。
总体而言，在研究过程中，49.8%接受检测的儿童血清学呈阳性。还有207例经PCR确认的COVID-19病例，其中12例（6.4%）严重到需要住院治疗。COVID-19的发病率在年龄<2岁的儿童中最高——每100人年16.1例（95%置信区间[CI]：12.5，20.5）——约为所评估的其他任何年龄组儿童发病率的三倍。此外，41例（19.8%）症状性SARS-CoV-2发作是再次感染，年龄较小的儿童对症状性再次感染的防护略好。在6至59个月大的儿童中，防护率为61%（率比[RR]：0.39，95%CI：0.2，0.8），而在5至9岁和10至14岁儿童中的防护率分别为64%（RR：0.36，0.2，0.7）和49%（RR：0.51，0.3，0.9）。
在这项基于社区的前瞻性儿科队列研究中，症状性和重症COVID-19的发生率在最年幼的参与者中最高，在5岁左右趋于稳定。再次感染占PCR阳性病例的很大比例，10岁以下儿童对症状性再次感染的防护更强。迫切需要为5岁以下儿童研发疫苗。
幼儿中COVID-19的负担如何，以及预防再次感染的情况如何随年龄变化？在这项对1964名0至14岁儿童的研究中，5岁以下儿童症状性和重症COVID-19的发生率最高，同时与10岁及以上儿童相比，对再次感染的防护也更强。鉴于与大龄儿童相比，5岁以下儿童感染和患重症的风险更高，迫切需要为他们研发有效的COVID-疫苗。
