Long COVID–19 syndrome is another vicious feature of COVID-19 infection, the mechanism remains unidentified. Several observational studies suggest that vaccinations might have protective and therapeutic effect on long COVID-19 and our study aimed to assess the influence of vaccination on COVID-19 patients. We performed an observational cohort study from October 2020 to July 2022, which included 503 patients (291 males and 212 females) with a median age of 65. They were hospitalized due to COVID-19 pneumonia and had persistent symptoms (after 1 month of COVID-19 infection. The clinical and demographic data including vaccination status collected during hospitalization and regular visits at the Community Healthcare Center dr. Adolf Drolc Maribor were analyzed. More non-vaccinated patients acquired long COVID-19 than vaccinated. Patients with type 2 diabetes suffered from long COVID-19 in a smaller percentage than patients without diabetes. Gender, inhalational therapy due to chronic pulmonary disease and the number of complications have significantly influenced long COVID-19 development and the mostly vaccinated patients were older and with asthma/COPD. Our study confirmed that vaccination is a safe and effective measure to prevent the severe progression of acute disease and to lower the incidence of developing long COVID.

In the aftermath of the COVID pandemic, post-COVID-19 syndrome (PCS) remains a challenge and may continue to represent a major health problem in the future. Moreover, the influence of type 2 diabetes and being overweight on PCS remains unclear. This study aimed to assess this influence. We performed an observational study from October 2020 to July 2022, which included 466 patients (269 males and 197 females) with a median age of 65. They were hospitalized due to COVID-19 pneumonia and had persistent symptoms after 1 month of COVID-19 infection. The patients were divided into four groups according to the study objectives: patients with type 2 diabetes, overweight patients, overweight patients with type 2 diabetes, and normal-weight patients without type 2 diabetes. The clinical and demographic data collected during hospitalization and regular visits at the Community Healthcare Center dr. Adolf Drolc Maribor were analyzed. Our results showed that type 2 diabetes patients had a more difficult course of treatment and longer hospitalization. Moreover, more type 2 diabetes patients underwent rehabilitation than the other study groups. The prevailing symptoms in our patients with PCS were dyspnea and fatigue, mostly in female patients with type 2 diabetes. Our study also showed that more women with type 2 diabetes and more overweight women with type 2 diabetes suffered from secondary infections. Further, more overweight patients were treated in the intensive care unit compared to the other groups. However, our study showed an interesting result that patients with type 2 diabetes had the shortest PCS durations. Type 2 diabetes and being overweight are risk factors for PCS onset and prolonged duration. Therefore, our data that revealed a shorter duration of PCS in type 2 diabetes patients compared to the other investigated groups was unexpected. We believe that answering this question regarding the results will enable us to improve PCS treatment in general.