ABSTRACT
Objective: To describe the elapsed time between vaccination against SARS-COV2 and development of COVID19 pneumonia. To analyse the relation between COVID19 pneumonia and the time between doses as well as with patient profile. Material and/or methods: Cross-sectional descriptive study of patients diagnosed with COVID19 pneumonia and correctly vaccinated who have been notified to SEFV-h. The search for cases was carried out using the FEDRA 3 application between January and September 2021. Results: 99 cases of pneumonia in correctly vaccinated patients were identified;of these, 75 were vaccinated with Comirnaty, 12 with Janssen, 9 with Vaxzevria and 3 with Spikevax. Fifty-seven percent of pneumonias occurred 60 to 129 days after vaccination with a maximum ranging from 90 to 99 days (median 96). For analysis of the time between doses, the 87 cases that required two doses to complete vaccination schedule were considered. Nine of them had more than 2 months between doses, while 78 had less than 1 month (in 54% of the 87 cases 21 days had passed). There was no apparent association with the frequency of developing pneumonia. Thirty-seven percent were women and 60% men. To assess age, the cases were distributed by decade. Thus, the age group >79 had the highest number of cases (52), while the groups 60-69 and 70-79 comprised 18 cases each. The least cases were in the remaining groups: 8 (50-59), 2 (40-49) and 1 (30-39). There was none in the lower age groups. Conclusions: The data indicate that most cases of vaccine failure with severe disease occur 3 months after vaccination. Compared to pre-vaccination data collected from other sources, a decrease in severe cases was observed, with unchanged patient profile in terms of age and sex.