Assignment of Neisseria meningitidis serogroups A, C, W135, and Y anticapsular total immunoglobulin G (IgG), IgG1, and IgG2 concentrations to reference sera

Abstract

Meningococcal serogroup-specific immunoglobulin G (IgG), IgG1, and IgG2 concentrations were assigned to three reference sera, CDC 1992, 89-SF, and 96/562, for meningococcal serogroups A, C, Y, and W135 via the method of cross standardization. The sum of the serogroup-specific IgG1 and IgG2 concentrations determined for the four meningococcal serogroups showed good agreement with the serogroup-specific IgG either determined here or as previously represented. Following the assignment of meningococcal serogroup-specific IgG1 and IgG2 concentration to these reference sera, a meningococcal serogroup-specific IgG1 and IgG2 enzyme-linked immunosorbent assay protocol was developed. The serogroup A and C specific subclass distribution of a panel of adult sera collected following vaccination with any combination of meningococcal serogroup C conjugate, bivalent, or tetravalent polysaccharide vaccines was determined. For the determination of serogroup W135 and Y specific subclass distribution, an adolescent panel 28 days following a single dose of either tetravalent polysaccharide or conjugate vaccine was used. The sum of the serogroup-specific IgG1 and IgG2 showed strong correlation with the serogroup-specific total IgG determined. The assignment here of IgG1 and IgG2 subclasses to these reference sera will allow more detailed evaluation of meningococcal conjugate and polysaccharide vaccines.

FIG. 1.

Comparison of the sum of IgG1 and IgG2 concentrations determined by the IgG subclass ELISA with IgG concentrations of antibodies to meningococcal serogroups A, C, Y, and W135 in adult sera.

FIG. 2.

Typical parallel curves obtained in the determination of meningococcal serogroup-specific IgG and IgG subclass in the reference sera CDC 1992, 89-SF, and 96/562.