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Pneumococcal polysaccharide-meningococcal outer membrane protein complex conjugate vaccine is immunogenic in infants
H Käyhty1, H Ahman, P R Rönnberg
1KTL, National Public Health Institute, Helsinki, Finland.
Insights
The tetravalent pneumococcal conjugate vaccine (PncOMPC) effectively elicits immune responses in infants and toddlers. Immunization schedules demonstrate significant antibody production against key pneumococcal serotypes.
Area of Science:
- Immunology
- Vaccinology
- Pediatric Infectious Diseases
Background:
- Pneumococcal conjugate vaccines are crucial for preventing invasive pneumococcal disease.
- The outer membrane protein complex (OMPC) of Neisseria meningitidis serves as a carrier protein for pneumococcal polysaccharides.
- Evaluating vaccine efficacy across different infant and toddler immunization schedules is essential.
Purpose of the Study:
- To assess the immunogenicity of a tetravalent pneumococcal conjugate vaccine (PncOMPC) in infants and toddlers.
- To compare immune responses elicited by different vaccination schedules in infants.
- To evaluate the response to a booster dose in infants and the efficacy of one versus two doses in toddlers.
Main Methods:
- A tetravalent pneumococcal conjugate vaccine (PncOMPC) containing serotypes 6B, 14, 19F, and 23F was administered to infants and toddlers.
- Infants received vaccinations at either 2, 4, 6 months (Group A) or 4, 6, and 14 months (Group B).
- Toddlers received one or two doses at 24 or 24 and 26 months, respectively. Immunoglobulin G (IgG) responses were measured using enzyme immunoassay (EIA).
Main Results:
- Infants showed significant IgG responses to types 14 and 19F after the first dose, and to types 6B and 23F after the second dose.
- A robust booster response was observed in infants receiving the 14-month dose, indicating successful immunologic priming.
- Toddlers exhibited similar immune responses to one or two vaccine doses as observed in infants.
Conclusions:
- The PncOMPC vaccine demonstrates good immunogenicity in both infants and toddlers across the studied schedules.
- Early infant vaccination primes the immune system, leading to effective responses upon booster administration.
- The vaccine appears effective in inducing protective antibody levels in young children, supporting its potential role in pneumococcal disease prevention.
Abstract:
Sixty-two infants and 31 toddlers were vaccinated with the tetravalent pneumococcal conjugate vaccine PncOMPC consisting of the capsular polysaccharide of pneumococcal types 6B, 14, 19F, and 23F conjugated to the outer membrane protein complex of Neisseria meningitidis. Infants were vaccinated at 2, 4, and 6 months (group A) or at 4, 6, and 14 months (group B); toddlers were vaccinated at 24 or at 24 and 26 months of age. The IgG responses to the four pneumococcal polysaccharide types were measured by EIA. In infants, types 14 and 19F induced a significant response after the first dose and types 6B and 23F after the second dose. A clearcut booster response was seen to the booster dose given at 14 months, indicating immunologic priming by the primary series at 2-6 months of age. The responses of the toddlers to one or two doses of the vaccine were very similar to the responses in infants.