 This study compares the effectiveness of passive immunization post-exposure to measles using different doses of polyclinal human immunoglobulin, and finds that an enzyme-linked immunosubant assay, ELISA, is more sensitive than the plaque reduction neutralization test, PINT, in measuring measles antibody titers. The study also finds that Australian immunoglobulin products for post-exposure prophylaxis meet consensus prescribed international thresholds, and suggests that a convenient standardized assay for determining measles titers in immunoglobulin products would be useful for future studies and comparisons.