ABSTRACT
Background This study aimed to estimate the effects of vaccine on reducing the mortality rate and the relationship between underlying diseases and death among long term care hospital residents during the Omicron epidemic.Methods This study included 2,507 inpatients at 18 long term care hospitals that experienced COVID-19 outbreaks more than twice in Daegu Metropolitan City and Gyeongsangbuk-do in Korea, from January 2022 to August 2022. Descriptive statistics were used to analyze participants’ demographic characteristics and mortality, which were expressed as percentages (%). Logistic regression analysis was performed to compare mortality, and the crude risk ratio (cRR) and adjusted risk risk (aRR) were estimated. The analysis model was adjusted for sex, age, region, history of Paxlovid priscription, vaccine status, reinfection, and presence, type, and number of underlying diseases.Results In terms of vaccination status, the aRR in the group with < 90 days after the 3 doses was 0.20 (CI:0.09–0.45) and ≥ 90 days was 0.14 (CI:0.06–0.32), that in the group with < 90 days after 4 doses was 0.18 (CI:0.06–0.43), compared with the non-vaccinated group. The fatality rate in the group prescribed Paxlovid was higher than that in the non-prescribed group. However, the difference was not statistically significant. The aRR of hypothyroidism was 5.75 (CI:1.10–30.13) and that of COPD and asthma were 2.84 (CI:1.15–6.99), compared with the group that did not have each underlying disease.Conclusion We confirmed the preventive effects of vaccination on death and the high risk of death from hypothyroidism, COPD, and asthma in COVID-19-confirmed patients in long term care hospitals.