Comparison of plaque reduction neutralisation test (PRNT) and measles virus-specific IgG ELISA for assessing immunogenicity of measles vaccination.

Background: Plaque reduction neutralisation test (PRNT) is a gold standard assay for measles antibodies. PRNT, however, is time-consuming and more difficult to standardise than ELISA.

Methods: PRNT results were obtained on pre- and post-vaccination sera from 501 measles-vaccinated infants. From this cohort a sub-set of 210 infants were selected for testing by ELISA, which was performed either manually or by an automated processor. Results were corrected for sampling proportion before comparing the assays.

Results: Seroconversion was detected by PRNT in 454 infants of whom 324 were estimated to have seroconverted by manual ELISA and 191 by automated ELISA It is recommended that ELISA negative post-vaccination samples are re-tested by PRNT to detect all seroconversions.