TABLE 4.

Neurovirulence of vaccines and new strains

Virus	TgPVR micea PD50 (log10)b	Cynomolgous macaques
		Clinical score (no. of paralyzed animals/ total no.)	Mean lesion score (SD)	P valuec
Sabin 3	>8.9	0/10	0.62 (0.66)
S15	>9.1	0/4	0.61 (0.63)	0.96
S16	NDd	0/4	0.42 (0.25)	0.41
Sabin 2	>8.9	0/4	0.27 (0.12)
S15/2	7.5	0/4	0.80 (0.26)	0.02
Sabin 1	7.6	0/6	0.63 (0.28)
S15/1	7.8	0/4	0.71 (0.29)	0.68

^aTg66-C57.

^bIntramuscular route.

^cStudent's t test.

^dND, not determined.