Objective: To evaluate the incidence of wheezing and overall respiratory morbidity in healthy infants born during the first peak of the coronavirus (COVID-19) pandemic, compared to infants born during the preceding year.
Methods: This was a single center retrospective birth cohort study to compare a cohort of children born between February-March 2020 (COVID-19 group) to a control group of children born between February-March 2019 (pre-COVID-19 group). At one year of age, we collected respiratory data using validated, parental, telephone questionnaires. Primary outcome: wheezing incidence and/or bronchodilator use. Secondary outcomes: recurrent wheezing, emergency-room visits, hospital admissions, pneumonia diagnosis, and admissions due to lower-respiratory-tract-infections (LRTI). We included the following covariate risk factors in the logistic regression models; atopy, daycare attendance, breastmilk feeding, parental smoking and gestational age.
Results: We enrolled 588 infants, 294 in each group (48% males). Demographic, perinatal, and atopic characteristics were similar between the groups. Compared to the pre-COVID-19 group, infants born during the COVID-19 period were significantly less likely to report wheezing and/or bronchodilator use (adjusted-OR, 0.4; 95% CI-0.27-0.58), recurrent wheezing episodes (adjusted-OR, 0.54; 95% CI-0.29-0.99), systemic steroid use, (adjusted-OR, 0.35; 95% CI-0.23-0.83), emergency-room visits (adjusted-OR, 0.33; 95% CI-0.16-0.66), LRTI admissions (adjusted-OR,0.18; 95% CI-0.05-0.66), or pneumonia diagnosis (adjusted-OR, 0.2; 95% CI-0.08-0.47).
Conclusions: This is the first study investigating wheezing and respiratory morbidity in healthy infants during the first COVID-19 pandemic year. Our study demonstrated a significant decrease in all aspects of respiratory morbidity. A longitudinal follow-up study to explore the subsequent impact of these findings, is warranted.