Abstract
WHAT IS ALREADY KNOWN ON THIS TOPIC? Pneumococcal conjugate vaccines (PCVs), including the 13-valent PCV (PCV13), effectively reduce the nasopharyngeal carriage of vaccine-type Streptococcus pneumoniae (S. pneumoniae) and prevent invasive pneumococcal disease in children. However, an increasing prevalence of non-vaccine serotypes and serotype replacement has been documented globally, with notable variations in the predominant replacement serotypes across different geographic settings. WHAT IS ADDED BY THIS REPORT? This study demonstrated that PCV13 vaccination significantly reduced the pharyngeal detection of S. pneumoniae among children with acute respiratory infections, with three to four doses decreasing the detection rate by 30.2%. This reduction encompassed both vaccine and non-vaccine serotypes. Additionally, non-PCV13 serotypes, particularly 10A and 15A/15F, were predominant in positive samples, underscoring the current dominance of non-vaccine serotypes in the study population. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE? The PCV13 program successfully reduced pneumococcal detection rates, particularly among children who complete the 3-4 dose series. Continued surveillance of circulating S. pneumoniae serotypes is essential to monitor serotype replacement patterns and develop future vaccination strategies.