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Immune responses of infants vaccinated with serotype 6B pneumococcal polysaccharide conjugated with tetanus toxoid

S T Sigurdardottir1, G Vidarsson, T Gudnason

  • 1Department of Immunology, National University Hospital, Reykjavik, Iceland.

The Pediatric Infectious Disease Journal
|July 1, 1997
PubMed

Insights

This study shows that the pneumococcal type 6B polysaccharide-tetanus toxoid conjugate (Pn6B-TT) vaccine is safe and effective in infants. It elicits functional antibodies and memory responses against Streptococcus pneumoniae.

Area of Science:

  • Immunology
  • Vaccinology
  • Pediatrics

Background:

  • Streptococcus pneumoniae causes severe infant infections like meningitis and pneumonia.
  • Infant immune response to pneumococcal polysaccharides is poor; conjugate vaccines show improved immunogenicity.
  • Rising antibiotic resistance necessitates effective pneumococcal vaccines.

Purpose of the Study:

  • To evaluate the safety and immunogenicity of a pneumococcal type 6B polysaccharide-tetanus toxoid conjugate (Pn6B-TT) vaccine in infants.
  • To assess the functional activity of antibodies generated by the Pn6B-TT vaccine.
  • To investigate the vaccine's ability to induce immunological memory.

Main Methods:

  • Two groups of healthy infants received Pn6B-TT vaccinations at different infant ages (3, 4, 6 months vs. 7, 9 months).
  • A booster dose was administered at 18 months.
  • Antibody levels (IgG, IgM, IgA) and functional opsonic activity were measured using ELISA, radioimmunoassay, and bacterial opsonization assays.

Main Results:

  • The Pn6B-TT vaccine demonstrated a good safety profile with no significant adverse reactions.
  • Vaccination led to significant increases in Pn6B-specific IgG and total antibodies, with higher responses in the later-dosed group.
  • Booster doses at 18 months induced robust secondary immune responses and functional antibody activity, correlating with antibody titers.

Conclusions:

  • The pneumococcal type 6B polysaccharide-tetanus toxoid conjugate (Pn6B-TT) vaccine is safe for infants.
  • Pn6B-TT successfully elicits functional antibodies against Streptococcus pneumoniae serotype 6B.
  • The vaccine induces immunological memory, indicating potential for long-term protection.
Abstract

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