Validity of Enzyme-Linked Immunosorbent Assay (ELISA) as a correlate of protection of meningococcal C conjugated vaccine in adolescents with HIV infection

The immunological response to meningococcal C conjugated vaccine can be evaluated by two different tests: the serum bactericidal antibody assay (SBA), which evaluates the qualitative bactericidal capacity of the antibodies, and the Enzyme-Linked Immunosorbent Assay (ELISA), which quantifies the specific serogroup C meningococcal immunoglobulin-G. Incompatibilities between the results of both tests have been reported. Technically, ELISA is simpler, safer, and easier to reproduce when compared to the SBA; thus, an assessment of the validity of ELISA as a protective correlate compared to the SBA gold standard should be performed. This study tested the validity of ELISA for the evaluation of the protective response to the C meningococcal conjugate vaccine in adolescents with HIV compared with the gold standard SBA, to evaluate the reliability of ELISA to infer the protection of the individual.