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Induction of Leptomeningeal Cells Modification Via Intracisternal Injection
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Neonatal immune response and serum bactericidal activity induced by a meningococcal conjugate vaccine is enhanced by

Siggeir F Brynjolfsson1, Stefania P Bjarnarson, Elena Mori

  • 1Landspitali, Department of Immunology, Reykjavik, Iceland.

Vaccine
|July 4, 2008
PubMed

Insights

Vaccination strategies using meningococcal serogroup C conjugate (MenC-CRM(197)) with adjuvants LT-K63 or CpG2006 effectively prime neonatal mice. This approach enhances immune responses and protective immunity against meningococcal disease.

Area of Science:

  • Immunology
  • Vaccinology
  • Microbiology

Background:

  • Neonates possess immature immune systems, necessitating early-life vaccination strategies.
  • Developing effective vaccines for infants against serious pathogens like meningococcal serogroup C is crucial.

Purpose of the Study:

  • To evaluate the immunogenicity of a meningococcal serogroup C polysaccharide conjugate (MenC-CRM(197)) in neonatal mice.
  • To compare the effects of adjuvants LT-K63 and CpG2006 on immune responses and protective efficacy.
  • To assess the impact of different immunization routes (subcutaneous and intranasal) on vaccine effectiveness.

Main Methods:

  • Neonatal mice were primed with MenC-CRM(197), with or without LT-K63 or CpG2006, via subcutaneous (s.c.) or intranasal (i.n.) routes.
  • Re-immunization was performed at 16 and 30 days post-priming.
  • Antibody levels, affinity maturation, antibody kinetics, and serum bactericidal activity (SBA) were measured to assess immune memory and protective efficacy.

Main Results:

  • The second and third doses of MenC-CRM(197) combined with either LT-K63 or CpG2006 significantly increased MenC-specific IgG antibody levels.
  • Adjuvant-combined vaccines induced higher antibody levels compared to MenC-CRM(197) alone.
  • Two doses of MenC-CRM(197) with LT-K63 or CpG2006 were sufficient to induce protective SBA levels, whereas three doses of MenC-CRM(197) alone were required.

Conclusions:

  • LT-K63 and CpG2006 adjuvants enhance neonatal antibody responses, affinity maturation, and immunological memory to MenC-CRM(197).
  • These adjuvants improve protective immunity, supporting the development of neonatal vaccination strategies against meningococcal disease.
  • Both s.c. and i.n. routes are effective for priming neonatal immune responses with MenC-CRM(197) and adjuvants.

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