Pediatric Invasive Pneumococcal Disease Spectrum Before Third-Generation Pneumococcal Conjugate Vaccine...

Area of Science:

• Pediatrics
• Infectious Diseases
• Vaccinology

Background:

• Pneumococcal conjugate vaccines (PCVs) have altered the landscape of invasive pneumococcal disease (IPD).
• Changes in serotype distribution and clinical presentation of IPD have been observed post-PCV implementation.
• This study examines IPD 15 years after PCV13 introduction, before next-generation PCVs.

Purpose of the Study:

• To describe the clinical profile of invasive pneumococcal disease (IPD) in children.
• To determine the serotype distribution of IPD cases.
• To evaluate the impact of PCV13 and the potential coverage of newer vaccines (PCV15, PCV20).

Main Methods:

• Prospective surveillance of IPD cases in 128 French pediatric wards (2017-2022).
• Data collection included demographics, clinical data, risk factors, and outcomes.
• IPD cases were categorized into meningitis, bacteremia without source, bacteremic pneumonia, and other IPD.

Main Results:

• Meningitis was the most frequent clinical entity (36.4%), followed by bacteremia without source (31.6%).
• Serotype 24F was the most prevalent overall (16.4%), and PCV20 non-PCV13 serotypes were associated with a significant proportion of deaths (33.3%).
• PCV13 serotypes (3, 19A, 19F) still accounted for 15.0% of cases, and PCV20 offers broader coverage than PCV13 and PCV15.

Conclusions:

• Serotype 24F, the leading cause of IPD in this study, is not covered by current third-generation PCVs.
• PCV20 demonstrates increased serotype coverage compared to PCV13 and PCV15, potentially impacting mortality.
• Understanding evolving serotype distribution is crucial for optimizing pneumococcal vaccination strategies.