Title : Impact of vaccination on the risk of severe forms of COVID -19 among elderly patients hospitalized in a Tunisian university hospital
Abstract:
Introduction: The COVID-19 vaccination campaign started in 2021 was a crucial step in significantly reducing mortality, especially among elderly people at high risk of serious forms. However, its impact on the progression of the disease has not been a frequent subject of research.
Objective: Determine the impact of vaccination against COVID-19 on the risk of severe form of Covid-19 in people aged over 65 years hospitalized in a Tunisian University Hospital.
Materials and methods: An exhaustive longitudinal descriptive study was carried out among patients suffering from COVID-19, aged over 65 and hospitalized in a Tunisian University Hospital during the period from 04/01/2021 to 08/15/2022. Sociodemographic and clinical data of patients were collected prospectively using a pre-established form.
Results: A total of 182 COVID-19 patients were identified. The median age was 73 years [68 – 79.25] with a male predominance. Sex ratio was 1.45. The median length of stay was 8 days [4 – 14]. In our sample, 83% of patients had comorbidities, the most commonly reported being hypertension (49.5%). Patients had non-invasive ventilation in 12.6% of cases, and intubation in 11.5% of cases. The overall mortality rate was 25%. The rate of patients vaccinated against covid-19 was 57.7%, of which 11% had a single dose, 36.8% received two doses and 9.9% had three doses. The mortality rate was 50% in vaccinated patients compared to 60.6% in those not vaccinated with a statistically insignificant difference. The use of intubation was more frequent in unvaccinated patients (11.7% vs 11.4%; p=0.957). Note that unvaccinated patients significantly required a length of hospitalization ≥ 9 days compared to those vaccinated (51.4% vs 30.4%; p=0.004).
Conclusion: The mortality rate, the use of intubation and the long duration of hospitalization were higher in unvaccinated patients who are likely to present severe forms of COVID-19. Thus, vaccination has an effect on reducing the risks of severe forms of COVID-19 in this age group.
