A Comparison of the Outcomes of COVID-19 Vaccinated and Nonvaccinated Patients Admitted to an Intensive Care Unit in a Low-Middle-Income Country.

Patients critically afflicted with coronavirus disease 2019 (COVID-19) often need intensive care unit (ICU) admission, despite comprehensive vaccination campaigns. The challenges faced by healthcare systems in low-middle-income countries, including limited infrastructure and resources, play a pivotal role in shaping the outcomes for these patients. This study aimed to meticulously compare outcomes between COVID-19 vaccinated and nonvaccinated patients admitted to the ICU. In addition, demographic factors and the ICU course influencing mortality were also assessed. A retrospective review of records from the COVID-ICU of Aga Khan University Hospital spanning July 2021-March 2022 included 133 patients. Statistical analyses, encompassing the Mann-Whitney U-test and chi-square/Fisher exact test, discerned quantitative and qualitative differences. Stepwise multivariable logistic regression models with forward selection identified factors associated with hospital mortality. Results revealed comparable cohorts: vaccinated (48.13%) and nonvaccinated (51.87%). Vaccinated individuals, characterized by advanced age and higher Charlson Comorbidity Index, exhibited more critical disease (89.1%; p value: 0.06), acute respiratory distress syndrome (96.9%; p value: 0.013) and elevated inflammatory markers. Despite these differences, both cohorts exhibited similar overall outcomes. Factors such as decreased PaO2/FiO2 ratio on admission and complications during ICU stay were significantly associated with in-hospital mortality. In conclusion, despite advanced age and increased frailty among vaccinated patients, their mortality rate remained comparable to nonvaccinated counterparts. These findings underscore the pivotal role of vaccination in mitigating severe outcomes within this vulnerable population.