Introduction: The vaccine's development has contributed to decrease the number of severe SARS-COV2 conditions.?Aims and objectives?To analyze the clinical impact of SARS-COV2 infection and vaccination in Cystic Fibrosis (CF) adult patients from Virgen del Rocío Hospital.

Methods: An observational descriptive analysis of clinical monitoring of our CF patients who underwent SARS- COV2 infection. Gender, genotype, comorbidities, modulator treatment, epidemiological wave, vaccination, diagnostic method, symptoms, hospital admission, lung function and nutritional condition were analyzed.

Results: 68 from 167 patients were infected (40,72%). 50% were male, 26.6% were lung transplanted and 34,4% were homozygous for the DF508 mutation and 40,6% were heterozygous. 67,2% were pancreatic sufficient, 32,8% had CF-related diabetes and 14,1% had liver disease. 34,4 % had a chronic bronchial infection by methicillin- susceptible Staphylococcus Aureus and 39,1% by Pseudomonas Aeruginosa. 56,3% weren't under CFTR modulators treatment. 50% of the infections were diagnosed during the 6th wave and 79.7% by an antigen test. 87,5% were symptomatic, and 2 patients needed a hospital admission. 95,58% were vaccinated, 23,5% with 4 doses. 4 patients were treated with molnupiravir. Before and 1 month after the infection the BMI was 22,36±2,90 and 22,21±3,19 (p=0,312) and the FEV1 was 77,12 ±19,27 and 76,34±18,51(p=0,446).1 month before and 6 months after infection the BMI was 22,24±2,95 and 22,59±2,96 (p=0,14) and the FEV1 was 76,16 ±18,75 and 76,58±18,73 (p=0,710).

Conclusions: Despite vaccination, 40% of our CF adult patients underwent SARS-COV2 infection, leading to a temporal lung function and nutritional condition worsening.