TABLE 3.

Evaluation of protective immunity conferred by DNA vaccine for WN virus in mice

Test	Plasmid and dosea (μg)	Titerb on wk p.v.:			Challenge methodc	% Survival	Avg survival time (days)
		3	6	9
I	pCBWN
	100.0	1:80	1:80	1:640	i.p.	100
	100.0	1:80	1:80	1:320	Mosq.	100
	pEGFP (control)
	100.0	<1:10	<1:10		i.p.	0	6.9
	100.0	<1:10	<1:10		Mosq.	0	7.4
II	pCBWN
	100.0		1:160		i.p.	100
	10.0, E		1:160		i.p.	100
	1.0, E		1:80		i.p.	100
	0.1, E		1:40		i.p.	100
	pEGFP (control)
	100.0		<1:10		i.p.	0	7.0

^aGroups of 10 ICR mice were immunized via a single i.m. injection or i.m. followed by electrotransfer (E). 

^bSerum neutralization titers of postvaccination (p.v.) pooled sera were determined as described in Materials and Methods. Week 9 sera were collected from the surviving mice 3 weeks after virus challenge. 

^cMice were challenged by i.p. injection of 1,000 LD₅₀ of virus or by exposure to the bite of three virus-infected mosquitoes (Mosq.).