COMPARATIVE MONKEY NEUROVIRULENCE OF SABIN TYPE-III POLIOVIRUS VACCINES

The paper presents a retrospective review of all monkey neurovirulence tests on type III oral poliovirus vaccines tested at this Institute since 1961. The results indicate that although occasional batches of vaccine from different manufacturers showed relatively high levels of neurovirulence for cynomolgus monkeys, when inoculated intraspinally, there was no consistent overall difference between vaccines from different manufacturers at SO+3 passage level. There was however a significant increase in neurovirulence with cell culture passage. The desirability of establishing a homotypic type III reference virus, of proven safety in the field, is emphasized. © 1979 The International Association of Biological Standardization.