Poliovirus antigenic hybrids simultaneously expressing antigenic determinants from all three serotypes.

We have constructed six hybrid polioviruses (PVs) modified to express PV type 2 and type 3 antigenic determinants on a PV type 1 (Mahoney) capsid. The hybrids were modified in neutralizing antigenic site (NAg) I and/or NAgII. They were viable, but impaired for growth in comparison to PV1 (Mahoney). Some hybrids modified to express type 2 and type 3 NAgI determinants simultaneously displayed some type 2 but no type 3 antigenicity (in addition to type 1 antigenicity associated with other antigenic sites). Hybrids modified to express a type 2 NAgI determinant and a type 3 NAgII determinant, or vice versa, displayed antigenic characteristics of all three serotypes, although expression of the modified NAgII determinant was weak. We conclude that it is possible to construct a viable hybrid PV simultaneously modified in NAgI and NAgII which expresses antigenic determinants of all three serotypes.