Is vaccination necessary for COVID-19 patients? A retrospective cohort study investigating reinfection rates and symptomatology in a tertiary hospital

Abstract

Background Durability of immune response by the COVID-19 natural infection and the necessity of vaccines in recovered patients are important inquiries for the healthcare provider. Research Design and Methods Here, we investigated the characteristics and the rate of cases with reinfection that have been admitted to our tertiary hospital. Results A total of 119985 patients were applied between March 2020 and May 2021. Of these patients, 32607 (27%, 32,607/119985) tested positive. A total of 27 (0.08%, 27/32607) patients were found to be reinfected beyond 90 days. Only one of these reinfected patients (0.003, 1/32607) had novel COVID-19 pneumonia and was hospitalized for the second time. Other 26 reinfected patients were followed up as outpatients. Conclusions COVID-19 reinfection is extremely rare. However, the reinfection may be severe in patients with immune deficiency. Healthcare providers may prioritize uninfected and immune-compromised patients for vaccination.