Table 1

Biological characterization of sPV1(M). Plaque reduction assay in the presence (+) and absence (−) of antibodies as described in (13). Anti-PV1(M) and anti-PV2(L) are neutralizing polyclonal antibodies specific for types 1 and 2 poliovirus, respectively. Neuropathogenicity of sPV1(M) andwt PV1(M) was assayed in hPVR-tg mice as described in (13). PLD₅₀ is defined as the amount of virus that caused paralysis or death in 50% of the inoculated mice.