Clinical and laboratory characteristics of hospitalized patients with COVID-۱۹ after vaccination in Quchan- Iran

Background: COVID-۱۹  is the latest and most important global health crisis, which challenged even the most advanced healthcare systems in the world. The mortality rate due to COVID-۱۹ in the first year of its outbreak was equal to the mortality rate due to the HIV epidemic and drug overdose in recent decades. Effective vaccination is the only solution to prevent infection and reduce the disease severity and mortality rate. The present study aimed to determine the clinical and laboratory characteristics of hospitalized patients with COVID-۱۹  after vaccination in Quchan County, Iran. Methods: This is an observational analytical study with a cross-sectional design (Ethical code: IR.MUMS.REC.۱۴۰۰.۲۶۸). The study population includes the one-year data of patients with COVID-۱۹ admitted to Musa Ibn Jafar Hospital in Quchan County (mid-۲۰۲۱). The data were divided into two groups of vaccinated (n=۱۲۳) and unvaccinated (n=۱۲۳). Three post-vaccination time windows of “no immunity”, “partial immunity”, and “full immunity” were defined to determine the length of hospitalization and death rate due to COVID-۱۹ based on the type of vaccine. The data were collected using a researcher-made checklist, surveying demographic information, underlying diseases, primary symptoms, date of vaccination, and the duration of post-vaccination infection. The data were collected from patients' medical files recorded in the archive system of the hospital, the SIB system, or by calling patients or their families. The data were analyzed in SPSS v.۲۲.  Results: The mean age of vaccinated patients was higher than that of unvaccinated patients. There was no significant difference between the two groups in terms of sex, occupation, place of residency, and marital status. Chest pain, muscle pain, and vomiting were significantly less common in vaccinated patients, while shivering was more common. The C-reactive protein (CRP) level was significantly higher in vaccinated patients, while the white blood cell (WBC) count was lower. Mortality rate and the length of hospitalization were significantly higher in unvaccinated patients. There was no linear relationship between the factors of age and sex and the mortality rate in any groups. Sinopharm (۷۳.۹۸%) and AstraZeneca (۱۷.۷%) were the most common vaccines. All death cases occurred in the full immunity time window (two weeks after receiving the second dose of vaccine) Conclusions: Vaccination can reduce the length of hospitalization and mortality rate in COVID-۱۹ patients. Therefore, further vaccination coverage is necessary for reducing the severity of disease, length of hospitalization, and mortality rate in these patients.