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Total and functional antibody response to a quadrivalent meningococcal polysaccharide vaccine among children
W J King1, N E MacDonald, G Wells
1Department of Pediatrics, Children's Hospital Eastern Ontario, University of Ottawa, Canada.
Insights
This study found that total antibody response is a good indicator of functional antibody in children over 18 months old after meningococcal C vaccination. Younger children may need revaccination.
Area of Science:
- Immunology
- Vaccinology
- Pediatrics
Background:
- Neisseria meningitidis serogroup C poses a significant public health risk.
- Quadrivalent meningococcal polysaccharide vaccines are used for prevention.
- Assessing vaccine effectiveness requires understanding antibody responses.
Purpose of the Study:
- To evaluate total and functional antibody responses to a quadrivalent meningococcal polysaccharide vaccine.
- To determine the correlation between total and functional antibodies in different age groups.
- To inform vaccination strategies for Neisseria meningitidis serogroup C.
Main Methods:
- Prospective study design with pre- and post-vaccination assessments.
- Inclusion of participants aged 0.5 to 19.9 years undergoing a public health immunization campaign.
- Measurement of total antibodies via enzyme-linked immunosorbent assay and functional antibodies via bactericidal assay.
Main Results:
- Significant increase in total capsular polysaccharide antibody one month post-vaccination across all age groups.
- Significant rise in bactericidal antibody, correlating with total antibody, observed in children aged 18 months and older.
- Bactericidal antibody titers were maintained at 1 year, while capsular polysaccharide antibody levels decreased substantially in children under 5 years.
Conclusions:
- Total capsular polysaccharide antibody concentration can serve as a surrogate for bactericidal antibody in children 18 months and older.
- Consideration for revaccination is recommended for children vaccinated before 18 months if ongoing risk exists.
- Further vaccine efficacy trials are necessary to establish serologic correlates of protection due to differing antibody dynamics.
Objective:
To determine total and functional serogroup C antibody response after vaccination with a quadrivalent meningococcal polysaccharide vaccine.
Design:
Prospective, before and after intervention study.
Subjects:
Study subjects were between the ages of 0.5 and 19.9 years, and were eligible for a community-wide public health immunization campaign against Neisseria meningitidis serogroup C.
Methods:
Total and functional antibody response was measured by enzyme-linked immunosorbent assay and bactericidal assay, respectively.
Results:
One month after vaccination, total capsular polysaccharide antibody significantly increased in all age groups; a significant rise in bactericidal antibody, that correlated with total capsular polysaccharide antibody, was seen in children 18 months of age and older. At 1 year bactericidal antibody titers were maintained but capsular polysaccharide antibody declined substantially in children younger than 5 years.
Conclusion:
Total capsular polysaccharide antibody concentration appears to be a useful surrogate measure of bactericidal antibody in children 18 months and older. Children who originally received the vaccine at less than 18 months of age should be considered for revaccination if there is a new or continuing risk of disease. Because of the differences in the total and bactericidal antibodies formed, vaccine efficacy trials are required to define which serologic measures are associated with protection.