Development of an alternative method to the monkey neurovirulence test for oral poliovirus vaccines.

Each oral poliovirus vaccine lot contains attenuated and small amounts of wildtype viruses. Vaccines containing more than a certain limit of wildtype viruses may cause a vaccine associated poliomyelitis. To provide safe vaccines for humans, each newly manufactured vaccine lot is tested in the monkey neurovirulence test. A certain point mutation on the poliovirus genome has been shown to be responsible for the attenuated phenotype of the vaccine virus. We developed a quantitative PCR method to determine the wildtype proportion at position 472 of poliovirus type 3 genome. This method possibly can be used as an alternative for the monkey neurovirulence test.