Plaque reduction neutralization test for measles antibodies: Description of a standardised laboratory method for use in immunogenicity studies of aerosol vaccination

BackgroundClinical trials of measles vaccination administered as aerosol are planned with the aim of obtaining licensure. Measles antibody levels will be measured using the plaque reduction neutralization test (PRNT) to assess antibody responses as a surrogate marker of efficacy.MethodsA working group examined laboratory protocols for measles PRNT in use at three reference centres and agreed to a standardised procedure, which was subsequently validated.ResultsAssay validation showed quantitative results varied approximately threefold both within and between assays. The lower limit of detection was approximately 20 milliInternational Units/mL.ConclusionsA standardised laboratory protocol for measles PRNT was established and validated for use in clinical trials of aerosolized measles vaccines.