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Published on: February 22, 2019

Effectiveness of pneumococcal polysaccharide vaccine for preschool-age children with chronic disease

A E Fiore1, O S Levine, J A Elliott

  • 1Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. abf4@cdc.gov

Emerging Infectious Diseases
|December 22, 1999
PubMed

Insights

The pneumococcal polysaccharide vaccine showed 63% effectiveness against vaccine-type invasive pneumococcal disease in children. It demonstrated higher 94% effectiveness against serotypes not included in a proposed protein conjugate vaccine.

Area of Science:

  • Pediatric infectious diseases
  • Vaccinology
  • Epidemiology

Background:

  • Pneumococcal polysaccharide vaccine (PPSV) is used to prevent invasive pneumococcal disease (IPD).
  • Understanding vaccine effectiveness is crucial for public health strategies.
  • Surveillance data provides insights into vaccine performance in real-world settings.

Purpose of the Study:

  • To estimate the effectiveness of the pneumococcal polysaccharide vaccine (PPSV) in children aged 2-5 years.
  • To evaluate vaccine efficacy against specific pneumococcal serotypes.

Main Methods:

  • Serotyping of Streptococcus pneumoniae isolates from the Pneumococcal Sentinel Surveillance System (1984-1996).
  • Comparison of disease incidence between vaccinated (n=48) and unvaccinated (n=125) children.
  • Calculation of vaccine effectiveness (VE) against vaccine-type IPD.

Main Results:

  • Overall VE against IPD caused by vaccine serotypes was 63%.
  • VE against serotypes in PPSV but not in a proposed 7-valent protein conjugate vaccine was 94%.
  • This suggests significant protection conferred by PPSV, particularly against specific serotypes.

Conclusions:

  • The pneumococcal polysaccharide vaccine provides moderate effectiveness against invasive pneumococcal disease in young children.
  • Higher effectiveness was observed against serotypes targeted by the PPSV but not by a newer conjugate vaccine formulation.
  • These findings support the role of PPSV in IPD prevention and inform vaccine development strategies.

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