The present invention is directed to methods, assays and compositions for implementing such methods and assays for assessing efficacy of individual components in multi-component vaccines and for assessing efficacy of a vaccine against a pathogen. In one aspect, the method of assessing efficacy of a vaccine against a pathogen is a quick assay that tests for an activity correlated with efficacy such as binding in an ELISA rather than requiring the time and expense of an assay that detects actual bactericidal activity. In another aspect, the method for testing the efficacy of an individual component in a multi-component vaccine includes obtaining an immune sample from a subject inoculated with the multi-component vaccine; blocking the portion of the immune sample that recognizes the individual component such as by addition of the individual component, and testing the efficacy of the immune sample to respond to the pathogen.