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Anti-PsaA and the risk of pneumococcal AOM and carriage

Satu Rapola1, Virva Jäntti, Mervi Eerola

  • 1Department of Vaccines, National Public Health Institute, Helsinki, Finland.

Vaccine
|August 19, 2003
PubMed

Insights

Higher levels of antibodies against Pneumococcal surface adhesin A (PsaA) in young children correlate with increased pneumococcal carriage. However, PsaA antibody levels at 12 and 18 months may reduce the risk of acute otitis media (AOM).

Area of Science:

  • Immunology
  • Pediatrics
  • Infectious Diseases

Background:

  • Pneumococcal surface adhesin A (PsaA) is a key antigen of Streptococcus pneumoniae, explored for vaccine potential.
  • Previous research in animal models suggests PsaA's role in pneumococcal infections.

Purpose of the Study:

  • To investigate the association between serum anti-PsaA antibody concentrations and the risk of pneumococcal carriage and acute otitis media (AOM) in children.
  • To evaluate how anti-PsaA levels at different ages (6, 12, 18 months) influence subsequent risks.

Main Methods:

  • The Finnish Otitis Media (FinOM) Cohort Study followed 329 children.
  • Serum samples were collected at 6, 12, and 18 months of age.
  • The risk of pneumococcal carriage and AOM was assessed in the subsequent 6 months.

Main Results:

  • Elevated anti-PsaA concentrations at 6, 12, and 18 months predicted increased pneumococcal carriage risk.
  • Higher anti-PsaA at 6 months was linked to a greater risk of pneumococcal AOM.
  • Conversely, higher anti-PsaA at 12 and 18 months appeared to decrease pneumococcal AOM risk.
  • Previous AOM episodes were identified as the strongest predictor of subsequent AOM.

Conclusions:

  • Serum anti-PsaA antibody levels show a complex relationship with pneumococcal carriage and AOM risk in children.
  • The timing of anti-PsaA antibody concentration is crucial, with early levels potentially increasing carriage and AOM risk, while later levels may offer protection against AOM.

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