Health implication of the COVID-19 pandemic for children with Cystic Fibrosis (CF) followed at CF center Copenhagen

<bold>Objectives:</bold> Amid the COVID-19 pandemic, Denmark applied an extending lockdown, prescribing isolation and strict health measures for patients at CF center Copenhagen. This study aimed to explore the impact of these measures on children with cystic fibrosis (CF). <bold>Methods:</bold> This single center cohort study enrolled children with genetically verified CF. Data collected March 2019 to March 2022 included SARS-CoV-2 testing and vaccinations, hospital visits, mortality, lung function (FEV1), and BMI. Positive cases completed a symptom questionnaire. Danish age-matched background population (BP) data was used for comparison. Linear mixed-effects models analyzed FEV1 and BMI trends. <bold>Results:</bold> Of the 105 children with CF, 88 (83%) were included (44% male, mean age 13) and 36 (41%) tested positive for SARS-CoV-2, compared to 68% in the BP (p<0.0001). Only three CF children were asymptomatic, but no children were hospitalized, in contrast to 0.4% of the BP. BP mortality rate was 0.001%, with no death in the CF cohort. 920 FEV1 and BMI measurements from 58 children able to perform spirometry was analyzed. FEV1 and BMI z-scores prior to lockdown were -0.8 and -0.2, respectively. A stable z-FEV1 and z-BMI were observed both before and during the lockdown. Among 5-11-year-olds, 56% were vaccinated, compared to 37% of the BP (p<0.0001). The vaccination rate for 12–18-year-olds was equal to the BP. <bold>Conclusion:</bold> The lockdown, including vaccination, self-isolation and testing, significantly reduced SARS-CoV-2 infection rates among children with CF exhibiting no severe cases. Notably, lung function and BMI remained stable. The necessity and relative effectiveness of each measure remain uncertain.