Health Significance of the COVID-19 Pandemic in People with Primary Ciliary Dyskinesia, A National Cohort Study

Introduction During the COVID-19 pandemic, Danish health authorities implemented nationwide lockdowns and recommended strict preventive measures, particularly for individuals with chronic lung disease. This national study evaluated the health impact of COVID-19 in people with Primary Ciliary Dyskinesia (pwPCD) compared with the Danish background population. Methods Genetically confirmed pwPCD of all ages who consented were included. Data from March 2019 to March 2022 covered SARS-CoV-2 test results, vaccination status, hospitalization, COVID-19 related morbidity, z-scores of forced expired volume in one second; z-FEV 1 , and mortality. SARS-CoV-2-positive participants completed a retrospective symptom-score questionnaire. Descriptive statistics and linear mixed-effects models were applied. Results Of 124 Danish pwPCD, 79 (64%) participated (44% male, median age 24.3, range 0.4-71 years). SARS-CoV-2 positivity was significantly lower in pwPCD (20%) compared to the background population (58%) (p<0.0001). Most infections (94%) were mild. Hospitalization and mortality rates were comparable (0.8% versus 0,8%; 0% versus 0.2%, respectively). Vaccination acceptance was high (92% versus 82%), though it varied by age. z-FEV 1 remained stable pre-pandemic (0.02/year, p=0.65) and during the pandemic (-0.03/year, p=0.44), with only a clinical negligible difference (-0.09/year, p=0.024). Discussion COVID-19 had minimal health impact on pwPCD, with fewer infections, high vaccination adherence, and stable lung function. These findings contrast with concerns about severe outcomes in chronic lung disease and may reflect adherence to preventive measures. Conclusion Stringent health measures and proactive care may effectively protect pwPCD during pandemics. Similar strategies could be applied in future pandemics to protect pwPCD or other chronic lung diseases.