Long-term Association of 13-Valent Pneumococcal Conjugate Vaccine Implementation With Rates of Community-Acquired Pneumonia in Children.

IMPORTANCE: In several countries, 5 years after 13-valent pneumococcal conjugate vaccine (PCV13) implementation, serotype replacement has been reported for invasive pneumococcal disease, which raises concerns about the long-term outcome of PCV13 implementation. The long-term effect of vaccination on community-acquired pneumonia (CAP) remains unknown.

OBJECTIVE: To assess the long-term outcome of PCV13 implementation on CAP in children.

DESIGN, SETTING, AND PARTICIPANTS: This quasi-experimental, population-based, interrupted time-series analysis was based on a prospective multicenter study conducted from June 2009 to May 2017 in 8 French pediatric emergency departments. All patients 15 years and younger with chest radiography-confirmed CAP were included.

EXPOSURES: Community-acquired pneumonia.

MAIN OUTCOMES AND MEASURES: The number of CAP cases per 1000 pediatric emergency department visits over time, analyzed using a segmented regression model, adjusted for influenza-like illness syndromes.

RESULTS: We enrolled 12 587 children with CAP, including 673 cases of CAP with pleural effusion (5.3%), 4273 cases of CAP requiring hospitalization (33.9%), 2379 cases of CAP with high inflammatory biomarkers (18.9%), and 221 cases of proven pneumococcal CAP (1.8%). The implementation of PCV13 in 2010 was followed by a sharp decrease in the frequency of CAP (-0.8% per month [95% CI, -1.0% to -0.5% per month]), from 6.3 to 3.5 cases of CAP per 1000 pediatric emergency department visits until May 2014, then a slight increase since June 2014 (0.9% per month [95% CI, 0.4%-1.4% per month]), until 3.8 cases of CAP per 1000 pediatric emergency department visits in May 2017. There were marked immediate decreases in cases of CAP with pleural effusion (-48% [95% CI, -84% to -12%]), CAP requiring hospitalization (-30% [95% CI, -56% to -5%]), and CAP with high inflammatory biomarkers (-30% [95% CI, -54% to -6%]), without any rebound thereafter.

CONCLUSIONS AND RELEVANCE: The changes associated with PCV13 use 7 years after implementation remain substantial, especially for CAP with pleural effusion, CAP requiring hospitalization, and CAP with high inflammatory biomarkers. Emerging non-PCV13 serotypes may be less likely involved in severe CAP than invasive pneumococcal disease.