Unveiling the dynamics of respiratory infections revealed by multiplex PCR testing during the COVID-19 pandemic in Taiwan, 2020-2023.

Background: The emergence of SARS-CoV-2 in late 2019 sparked the global COVID-19 pandemic, leading to varied vaccine policies worldwide. The evolving patterns of respiratory pathogens, aside from SARS-CoV-2, during the pandemic have had a significant impact on the development of vaccine strategies. Methods: This study explores the landscape of respiratory pathogens, encompassing SARS-CoV-2, respiratory syncytial virus (RSV), and influenza viruses, through a retrospective analysis of data obtained from the BioFire Respiratory Panel 2.1 (RP 2.1) at China Medical University Hospital (Taichung, Taiwan) spanning from January 2020 to November 2023. Results: Among the 7950 respiratory samples studied, pediatric cases exhibited higher positivity (64.9%, 2488/3835) and mixed detection rates (43.8%, 1090/2488) than adults. Annual mixed detection rates increased (27.9–48%). Prevalence analysis revealed diverse patterns across age groups, with higher rates in pediatrics. Notably, human rhinovirus/enterovirus predominated (48.1%). Mixed detection illustrated viral co-detections, notably with parainfluenza viruses and adenovirus. Government policies and pandemic dynamics influenced infection patterns, with RSV resurgence after May 2022. Age-specific RSV detection demonstrated a shift, influencing vaccine considerations. Amid global vaccine initiatives, RSV's increasing trend in adults warrants attention. Conclusions: This comprehensive analysis emphasizes the importance of multiplex PCR testing in shaping targeted vaccination strategies during evolving respiratory pathogen landscapes.