The Effectiveness of Covid-19 Vaccines in Improving the Outcomes of Hospitalized Covid-19 Patients

Background: With the rapid spread of coronavirus disease 2019 (Covid-19), most countries took extreme measures to control and limit this disease. Equitable access to safe and effective vaccines is critical to ending the Covid-19 pandemic. The ministry of health program in Saudi Arabia aimed to cover 17.4 million adults (70% of the adult population of Saudi Arabia) by the third quarter of 2021. We investigated the impact of Covid-19 vaccine on the clinical course and outcomes of the admitted confirmed Covid-19 patients, in comparison to non-vaccinated patients.

Methodology: A retrospective cross-sectional record review was conducted for all hospitalized confirmed Covid-19 patients at Dammam medical complex (eastern province, Saudi Arabia) from june to july 2021. Two groups were studied according to the vaccination status (i.e. vaccinated and non-vaccinated). Information regarding comorbidities, length of stay, high oxygen requirements, ICU admission, and mortality data were collected.

Results: The sample included a total of 260 admitted confirmed Covid-19 cases. The mortality was significantly lower in the vaccinated group versus the non-vaccinated group with an OR 0.378 (CI 0.154-0.928). In addition, the OR of ICU admission was 0.476 (CI 0.218-1.042) and OR of endotracheal intubation was 0.561 (CI 0.249-1.265), but these did not reach statistical significance. We also detected a statistically significant relationship between mortality regardless of vaccination status-and age ≥ 65 years (P=0.000, OR=7.51; 95% CI 3.13 to 18.04), chronic kidney disease (P=0.010, OR=5.62; CI 1.52 to 20.79), and renal transplant (P=0.037, OR=10.17; CI 1.15 to 89.76). Of note, most of our vaccinated patients received only a single dose (85%).

Conclusion: There is a significant reduction in mortality cases as well as less complicated hospital course among the vaccinated group, in spite of the fact that most of our admitted patients had only a single vaccine shot. An inferior response to the vaccines was observed in the elder, chronic kidney disease, and renal transplant patients, hence the poorer outcomes in comparison to other patients.