Risk factors and the impact of vaccination on mortality in COVID-19 patients

The novel coronavirus disease (COVID-19) pandemic has had a profound global impact economically, socially, and in many other areas. As vaccines are developed and introduced, their effect on the disease on both, the global and individual scale is a subject of intense curiosity. This study aimed to evaluate the relationship between risk factors for hospitalization, disease severity, and vaccination status in COVID-19 inpatients in a pandemic hospital.

Patients hospitalized for COVID-19 between June and September 2021 were retrospectively analyzed in three groups: unvaccinated, incompletely vaccinated, and fully vaccinated. Disease severity was classified as moderate, severe, or critical according to World Health Organization criteria, and mortality risk factors and the prognostic effect of vaccination were analyzed.

The study included 486 patients, 228 women (46.9 %) and 258 men (53.1 %), with a mean age of 55.4 ± 16.5 years. Of these, 264 patients (54.3 %) were unvaccinated, 147 (30.2 %) were incompletely vaccinated, and 75 (15.4 %) were fully vaccinated. Older age, higher Charlson Comorbidity Index, greater disease severity, and being unvaccinated or incompletely vaccinated were associated with higher mortality.

The results of our study indicate that age, disease severity, comorbidities, and vaccination status were factors affecting COVID-19 mortality. Our findings support that full vaccination reduces COVID-19 -related mortality rates, disease severity, and length of hospital stay. However, large-scale studies with larger patient populations are needed (Tab. 2, Ref. 22).