TABLE 3.

Mortality rates and average survival times of CD-1 mice of various ages infected with different SB E2 mutants^a

Type of inoculation and virus	Result for mice of the following age at infection:
	6 daysb		10 daysc		21 daysd
	% Mortality	AST (days)	% Mortality	AST (days)	% Mortality	AST (days)
Subcutaneous
TR339	100	6.1 ± 1.0	NDe		0
39-E2H55	100	6.8 ± 1.3	ND		0
39-E2K70	85.7	8.3 ± 1.9	ND		0
39-E2H55K70	100	1.5 ± 0.4	ND		100	7.0 ± 0.7
39-E2R1	41.7	9.1 ± 1.7	ND		0
39-E2R114	83.3	10.5 ± 1.4	ND		0
39-E2K181	50	9.3 ± 1.4	ND		0
39-E2H55R1	ND		ND		0
39-E2H55R114	ND		ND		0
39-E2H55K181	ND		ND		0
Intracranial
TR339	100	6.0 ± 1.0	83.3	6.7 ± 2.4	0
39-E2H55	100	5.8 ± 1.3	81.8	6.3 ± 1.2	0
39-E2K70	100	3.9 ± 1.0	100	4.8 ± 0.9	0
39-E2H55K70	100	2.3 ± 0.5	100	2.8 ± 0.4	100	6.2 ± 0.8
39-E2R1	100	6.4 ± 1.4	63.6	6.4 ± 2.0	0
39-E2R114	100	5.9 ± 2.0	100	5.1 ± 0.9	0
39-E2K181	100	4.7 ± 0.9	81.8	4.8 ± 0.8	0
39-E2H55R1	ND		45.4	7.0 ± 2.0	0
39-E2H55R114	ND		45.4	8.8 ± 1.3	0
39-E2H55K181	ND		81.8	6.1 ± 1.7	0

^aMice were infected with equal dilutions of each stock of virus as described in Materials and Methods. Each experiment was performed at least twice with similar results.

^bEach group contained 21 to 24 mice.

^cEach group contained 10 mice.

^dEach group contained 5 mice.

^eND, not determined.