Respiratory Function Analysis Of Young Adults Post-Covid-19 Infection And After Immunization: An Observational Prospective Study

RESEARCH OBJECTIVES: To prospectively analyze respiratory function outcomes of young adults post-COVID-19 infection and follow up these individuals after COVID-19 immunization. DESIGN: Observational prospective cohort study (partial results from FIT-COVID Study). Participants were recruited after a minimum of 15 and maximum of 180 days of diagnosis by positive PCR test. After a minimum of 6 weeks from the second shot of COVID-19 vaccine participants were once again recruited to evaluations. The Ethical Institutional Review Board approved the study (number: 38701820.0.0000.5402). SETTING: a Physical Therapy public outpatient clinic in Brazil. PARTICIPANTS: We included male and female participants, aged 20–40 years after mild or moderate clinical COVID-19 and infection including slight clinical symptoms, fever, or respiratory symptoms, with previous positive PCR test and that were not admitted to intensive care unit (n=31). An age-matched healthy control group that was negative for COVID-19 was also recruited (n=39). INTERVENTIONS: Dyspnea was measured by the Modified Medical Research Council (MRC). Saccharin transit time test (STT) was performed to evaluate mucociliary transportability. Spirometry was performed using a digital spirometer. MAIN OUTCOME MEASURES: Primary outcomes included pulmonary function evaluated by Forced Expiratory Volume in 1 Second (FEV1), Forced Vital Capacity (FVC) FEV1/FVC ratio. Secondary outcomes included STT (in minutes) and MRC score. RESULTS: Post-COVID19 group increased FEV1% between baseline and follow up (77.37%±17.6 vs 87.44%±10.28; p=0.003) and presented significant lower values than CG (86.47%±11.433 vs 87.68%±9.29). For STT no differences were observed between groups (p=0.257). Dyspnea scores decreased for Post-COVID19 group between baseline and follow up (0.44±0.61 vs 0.17±0.38; p=0.042) but no differences between groups were observed (p=0.57). CONCLUSIONS: Pulmonary function was reduced in young adults Post-COVID-19 but improved over follow up analysis. Mucolciliary clearance and dyspnea was not impaired in young adults Post-COVID-19 and did not suffered changes after immunization. AUTHOR(S) DISCLOSURES: None of the authors have any conflicts of interests.