Invasive Pneumococcal Disease and Impact of 7- and 13-Valent Pneumococcal Conjugate Vaccines in Singapore Children Over 24 Years

Category	Detail
Condition	Invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae
Key Mechanisms	Serotype-specific pneumococcal conjugate vaccines (PCV7, PCV13) reduce IPD incidence; serotype replacement (notably serotype 19A) occurs post-vaccination
Target Population	Children aged <17 years in Singapore, especially ≤2 years
Care Setting	Pediatric hospital and national immunization program context

Introduction of PCV7 and PCV13 into Singapore's National Childhood Immunisation Schedule (NCIS) significantly reduced IPD incidence in children ≤2 years from 13.3 to 4.7 per 100,000.
IPD cases caused by PCV7 serotypes declined markedly from 68.0% to 22.0%, and PCV13 serotypes from 80.5% to 70.2% after vaccine introduction.
Serotype 19A increased substantially post-PCV13 introduction, representing 38.7% of IPD cases, indicating ongoing challenges with serotype replacement.

Laboratory confirmation of IPD by isolation of viable pneumococci from sterile sites such as blood, cerebrospinal fluid, pleural or peritoneal fluid, bone, or joints.

Implementation of age-appropriate pneumococcal conjugate vaccination schedules (2+1 doses) as per national immunization guidelines.

Robust IPD surveillance to monitor disease incidence, serotype distribution, and vaccine impact.
Monitoring for serotype replacement, particularly emergence of serotype 19A.

Risk of serotype replacement leading to disease caused by non-vaccine serotypes despite vaccination.
Incomplete vaccination may reduce vaccine effectiveness.

Children aged <17 years in Singapore, with focus on those ≤2 years

Complete vaccination with PCV7 or PCV13 reduces IPD incidence; however, vigilance for serotype 19A and other emerging serotypes is necessary.

Ensure timely and complete administration of PCV doses according to age-specific schedules.
Maintain comprehensive surveillance systems to detect changes in IPD incidence and serotype prevalence.
Adapt vaccination strategies based on surveillance data to address serotype replacement.
Educate healthcare providers and caregivers on the importance of vaccination and completion of vaccine schedules.

Clinical Scorecard: The Burden of Invasive Pneumococcal Disease and the Effects of 7- and 13-Valent Pneumococcal Conjugate Vaccines in Singaporean Pediatric Population Over 24 Years