Non-COVID Admissions to the ICU After COVID Vaccination: A Multicenter Study

Introduction: The vaccination drive for COVID-19 was launched in India after the authorization of ChAdOx1 nCov-19 (Covishield), an adenoviral vector vaccine, and BBV152 COVID-19 (Covaxin), an inactivated virus vaccine. As stated by the CDC, vaccine-related adverse events can happen. In this study, we aimed to assess the timing of the COVID vaccination and admission diagnosis and their effect on ICU mortality. The time from vaccination can help identify adverse events directly related to vaccination. Methods: A retrospective cohort study was conducted across four centers in India. Patients who took the first or second dose of any vaccines and were admitted with non-COVID illness to the ICU were included in the study. Patients were categorized based on the time interval from vaccination as ≤42 days or >42 days. The primary outcome was ICU mortality. The secondary outcomes were the length of ICU stay and duration of mechanical ventilation.

Results: A total of 175 patients were included in the study. The mean age was 53.49 (15.89) years, and 61.14% were males. The ICU mortality was 24.57% (18.38% to 31.63%). Thromboembolic events such as acute coronary syndrome (ACS), cerebrovascular accident (CVA), and mesenteric ischemia were seen in 7.43%, 7.43%, and 1.14% of patients, respectively. Six patients (3.43%) developed neuromuscular illness. The mortality was higher in patients >66 years, followed by ≤35 years of age when admitted ≤42 days of vaccination (p=0.008). The mortality was higher in cerebrovascular disorders and was clinically significant (p<0.001).

Conclusion: Patients developed thromboembolic events and neuromuscular diseases requiring ICU admission post-COVID vaccination. We observed a significantly higher mortality in the age groups >66 years and ≤35 years when admitted within 42 days of COVID vaccination. Patients admitted with cerebrovascular diseases also had higher mortality.