A comparison of pulmonary function pre and post mild SARS-CoV-2 infection among healthy adults

Background: SARS-CoV-2 infection frequently involves the respiratory system and may impact on pulmonary function tests (PFT) of recovered individuals. Studies which compare post-COVID-19 PFT to pre-illness measurements are scarce. The primary objective of this study was to assess the effect of COVID-19 on PFT soon after infection. Methods: In this prospective observational study, PFT were measured early following recovery from COVID-19 among healthy military aircrew. Spirometry values were compared to pre-COVID-19 measurements, and abnormality rates of lung volumes and diffusion capacity for carbon monoxide (DLCO) were assessed. Results: The study included 252 aviators, 97.6% males, mean age 34.9-years, following recovery from SARS-CoV-2 infection. Participants manifested mild symptoms (79.4%) or were asymptomatic (20.6%). Post-COVID-19 spirometry results 10.79 ± 5.67 days following infection were compared to measurements performed 41.3 ± 28.59 months earlier. Pre- and post-COVID-19 results were comparable, with similar minimal abnormalities rates (2% and 4.4%, respectively). In addition, there were no restrictive abnormalities following infection, and just 7.7% of individuals had a marginally low DLCO of 70–80% of predicted. Conclusion: Among vaccinated, healthy adults, mild COVID-19 had no significant impact on PFT early post-infection. The data suggest that systematic PFT testing might not be necessary for asymptomatic healthy individuals who recovered from mild COVID-19.