Chimeric Japanese Encephalitis Virus SA14/SA14-14-2 Was Virulence Attenuated and Protected the Challenge of Wild-Type Strain SA14

Table 1

LD₅₀ of neurovirulence and neuroinvasiveness of chimeric virus and parental viruses.

Dilution of virus	JEV SA14-14-2		JEV SA14		JEV SA14/SA14-14-2
	(No. of dead mice/no. of total mice)
	i.c.	s.c.	i.c.	s.c.	i.c.	s.c.
10^0	0/6	0/6	NA	NA	0/6	0/6
10^1	0/6	0/6	NA	NA	0/6	0/6
10^2	0/6	0/6	6/6	6/6	0/6	0/6
10^3	0/6	0/6	6/6	6/6	0/6	0/6
10^4	0/6	0/6	6/6	6/6	0/6	0/6
10^5	0/6	0/6	6/6	6/6	0/6	0/6
10^6	NA	NA	6/6	0/6	NA	NA
10^7	NA	NA	1/6	0/6	NA	NA
Titer of virus (log10 PFU)	6.60	6.60	6.75	6.75	6.54	6.54
LD50 (PFU)	>1.2 ∗ 10^5	>4.0 ∗ 10^5	0.05	2.1	>1.0 ∗ 10^5	>3.5 ∗ 10^5

NA: not available (represents that the experiments were not carried out).