Severe COVID-19 pneumonia is a significant contributor to both extubation failure and mortality. In this context, gaining knowledge about the clinical features, laboratory profiles, and immunopathology of bronchoalveolar lavage fluid (BALF) can potentially enhance the prognosis of patients with the condition. The severity of COVID-19 has been linked to various significant changes in the immune system of the host. These changes include a decrease in the number of lymphocytes, an imbalanced distribution and activation of specific types of T-cells, disruption of the B cell population, and increased levels of proinflammatory cytokines in the blood. In addition, several data indicate that the T-cell responses unique to SARS-CoV-2 play an essential role in influencing the development and progression of COVID-19. Although the exact characteristics of T-cell responses are not yet fully understood, it is widely accepted that SARS-CoV-2 is a major trigger in most patients, with CD4 responses being more prominent than CD8. In this case report, a 96-year-old male presented to the hospital with a chief complaint of breathing difficulty. A diagnosis of severe COVID-19 was later established based on the initial clinical, laboratory, and radiological findings. The patient’s vitals continued to deteriorate after the discontinuation of treatment and was finally declared dead, with BALF CD4 laboratory results being a significant factor.