Admission to Intensive Care Unit, Intubation and Pneumonia Development Status in Patients with COVID-19 Diagnosis According to Vaccination Status: The Istanbul Sample

Abstract

Introduction: The COVID-19 pandemic, which has been a global threat for more than two years, continues to impose a heavy burden on health services with its discovered and yet undiscovered various features, despite the measures to prevent, control, and avoid the spread of the disease. This study aimed to evaluate the clinical course, pneumonia development status, intubation status, and hospitalization based on the demographic characteristics and vaccination status of the COVID-19 cases who underwent SARS-CoV-2 variant analysis in Istanbul.Materials and Methods: The study included 12.709 cases over the age of 18 in Istanbul, for whom variant analysis was performed between 1 and 15 September 2021.Results: Of the cases, 4296 (33.8%) were fully vaccinated, 2082 (16.4%) were partially vaccinated, 1544 (12.1%) were unvaccinated (at least one dose of vaccination and less than 14 days past the last vaccination date), while 4787 (37.7%) did not get any vaccine for COVID-19. Of the 12.709 cases examined, 176 (2.4%) were admitted to the intensive care unit, 108 (1.5%) were intubated, 292 (3.9%) developed pneumonia, and 600 (4.7%) were followed up in the hospital. Delta variant was detected in 10.862 (85.5%) cases. In the logistic regression model created with variables that may affect intensive care unit admission, intubation, pneumonia development, and hospital follow-up, it was found that intensive care unit admission was 1.90 times higher for males than females, 1.09 times for all ages, and 1.85, 2.01, and 6.51 times higher for partially vaccinated, unvaccinated, and never vaccinated patients compared to fully vaccinated patients, respectively. Intubation was 1.66 times more common in males than in females, 1.09 times in all ages, and 1.99, 2.09, and 6.06 times higher in partially vaccinated, unvaccinated, and never vaccinated patients compared to fully vaccinated patients, respectively. The risk of pneumonia development was 1.07 times higher for all ages and 1.70, 2.15, and 4.80 times higher for partially vaccinated, unvaccinated, and never vaccinated compared to fully vaccinated, respectively. The risk of being followed in the hospital instead of the home was 1.37 times more common in men than in women, 1.09 times in all ages, and 2.14, 2.61, and 6.23 times higher in partially vaccinated, unvaccinated, and never vaccinated patients compared to fully vaccinated, respectively.Conclusion: Fully vaccinated individuals have the least risk for admission to the intensive care unit, intubation, pneumonia, and hos-pitalization; however, the risk is increased in those who are partially vaccinated, unvaccinated, and never vaccinated. In conclusion, individuals protected by vaccines have a milder disease course for different variants, even if they have COVID-19 infection.