TABLE 3.

Viral titers in the CNS of the mice infected with pDA, DApB, and DApBL2M

Time postinfection	Titer (PFU/g)a
	pDA		DApB		DApBL2M
	Brain	Spinal cord	Brain	Spinal cord	Brain	Spinal cord
1 wk	3.3 × 104	2.6 × 104	1.6 × 104	1.7 × 104	—b	—
1 mo	2.7 × 103	1.5 × 104	6.6 × 102c	—	—	—
4 mo	4.6 × 103	1.6 × 105	—	—	—	7.3 × 102cd

^aMean from three mice at each time point. 

^b—, below the detection limit. 

^cInfectious virus was isolated from one of three mice. 

^dSequence analysis demonstrated that the virus had a single amino acid mutation at position 171 (R to G) that differed from the original DApBL2M virus used to infect the mice.