Comparison of a monoclonal antibody-based IgM capture ELISA with a neutralization assay for assessing response to trivalent oral poliovirus vaccine.

Monoclone-based IgM capture ELISAs were developed for each of the three poliovirus serotypes and compared with a neutralization assay for detecting response to trivalent oral poliovirus vaccine among 224 infants. The IgM-based response rates were significantly higher than the neutralizing antibody-based rates: 95% versus 83% to poliovirus type 1, 99% versus 94% to poliovirus type 2, and 89% versus 59% to poliovirus type 3. IgM responses to the first vaccine dose were significantly associated between serotypes, suggesting that some of the discordance may reflect a heterotypic IgM response. When the response rates in 4 vaccine formulation groups were compared, group differences using the two assays were similar for poliovirus types 1 and 2 but not for type 3. Therefore, IgM results using these assays may not be adequate substitutes for neutralizing antibody results when determining vaccine response.