Background: Community-acquired pneumonia (CAP) is a leading cause of pediatric morbidity and mortality, particularly in developing countries. The COVID-19 pandemic, with its extensive non-pharmaceutical interventions (NPIs), has significantly altered respiratory infection patterns. This study explores the pandemic’s impact on severe pediatric pneumonia cases and the potential effects of NPIs on respiratory diseases. Methods: We report a case series of 48 pediatric patients with severe pneumonia, presenting in two groups: 13 patients from September to November 2023 and 35 patients from December 2022 to January 2023. Results: The median age was 6 years. Common symptoms included cough and fever, with 76.9% reporting recent upper respiratory infections. Many patients deteriorated rapidly, requiring intensive care. Streptococcus pneumoniae was the most common pathogen identified. Significant interventions included chest tube insertions, video-assisted thoracoscopic surgery (VATS), and thrombolytic therapy. The study noted a rise in necrotizing pneumonia (NP) and severe complications, including respiratory failure and multi-organ dysfunction, with a 4.1% mortality rate. Discussion: The study suggests that pandemic-related changes in respiratory infection patterns, particularly reduced influenza and altered bacterial coinfection rates, may have led to an ”immunity debt”. This phenomenon could result from weakened immune responses due to reduced exposure to common pathogens during the pandemic, leading to more severe bacterial infections post-pandemic. Conclusion: The findings emphasize the need for vigilance in monitoring respiratory infections in children post-pandemic. Enhanced vaccination, timely diagnosis, and effective treatment are essential for managing the evolving challenges of pediatric pneumonia in the COVID-19 aftermath.