Paediatrics and Child Health, Royal College of Surgeons, Dublin, Ireland.
Children's Health Ireland, Dublin, Ireland.
Pediatr Allergy Immunol. 2023 Sep;34(9):e14013. doi: 10.1111/pai.14013.
The CORAL study is a cohort of infants born during the first weeks of the first SARS-CoV-2 (COVID-19) lockdown. This cohort has had lower antibiotic exposure, higher breastfeeding rates and lower infection rates, especially in the first year of life. We hypothesized that the altered early-life environment of infants born during lockdown would change the incidence of allergic conditions.
This longitudinal, observational study followed 365 infants born between March and May 2020 from enrolment to the age of 2 years. Infants attended three research appointments at 6-, 12-, and 24-months and completed detailed questionnaires. At research appointments, children had skin prick testing, and atopic dermatitis (AD) assessment. Statistical analysis focused on changes within the group at different time points, the influence of specific environmental factors on allergic risk and compared the incidence of atopic conditions with a pre-pandemic Irish infant cohort, BASELINE.
AD was more common in CORAL group at both 12 (26.5% vs. 15.5%; p < .001) and 24 months (21.3% vs. 15.9%; p = .02) compared with pre-pandemic BASELINE cohort. Within the CORAL group, those with AD at both 12- and 24-month appointments had a more severe AD phenotype associated with a higher risk of allergic sensitization. There was less milk (0% vs. 1%; p = .09), peanut (0.6% vs. 1.8%; p = .3), and egg allergy (0% vs. 2.9%; p < .001) in the CORAL group at 24 months compared with the BASELINE cohort. Aeroallergen sensitization increased between 12 and 24 months in the CORAL cohort (1.5% vs. 8.9%; p < .001), as did parent-reported wheezing episodes (9% vs. 24%; p < .001).
Despite higher AD incidence in the CORAL cohort, the incidence of food sensitization and allergy are lower than expected pre-pandemic rates possibly reflecting the early introduction and maintenance of dietary allergens enhanced by changes in infant infections, antibiotic use, and breastfeeding in the first 2 years of life in the group. These beneficial effects of the lockdown could be outweighing the expected risk of less early-life microbial encounters outlined by the hygiene hypothesis.
CORAL 研究是一个由在第一波 SARS-CoV-2（COVID-19）封锁期间出生的婴儿组成的队列。该队列的抗生素暴露水平较低，母乳喂养率较高，感染率较低，尤其是在生命的第一年。我们假设，封锁期间出生的婴儿的早期生活环境的改变会改变过敏疾病的发病率。
这项纵向、观察性研究从招募开始，跟踪了 2020 年 3 月至 5 月间出生的 365 名婴儿，直到他们 2 岁。婴儿在 6、12 和 24 个月时参加了三次研究预约，并完成了详细的问卷。在研究预约时，孩子们进行了皮肤点刺测试和特应性皮炎（AD）评估。统计分析主要集中在不同时间点的组内变化、特定环境因素对过敏风险的影响，并将特应性疾病的发病率与大流行前的爱尔兰婴儿队列 BASELINE 进行了比较。
在 12 个月（26.5%比 15.5%；p<0.001）和 24 个月（21.3%比 15.9%；p=0.02）时，CORAL 组的 AD 更为常见，与大流行前的 BASELINE 队列相比。在 CORAL 组中，在 12 个月和 24 个月时都患有 AD 的婴儿，其 AD 表型更为严重，与过敏致敏的风险更高相关。与 BASELINE 队列相比，CORAL 组在 24 个月时的牛奶（0%比 1%；p=0.09）、花生（0.6%比 1.8%；p=0.3）和鸡蛋过敏（0%比 2.9%；p<0.001）更少。在 CORAL 队列中，气传过敏原致敏在 12 至 24 个月间增加（1.5%比 8.9%；p<0.001），父母报告的喘息发作也增加（9%比 24%；p<0.001）。
尽管 CORAL 队列的 AD 发病率较高，但食物致敏和过敏的发病率低于大流行前的预期水平，这可能反映了在该队列中，婴儿感染、抗生素使用和母乳喂养在生命的头 2 年发生了变化，从而更早地引入和维持了饮食过敏原。封锁带来的这些有益影响可能超过了卫生假说所概述的预期的早期生活中微生物接触减少的风险。
