Table 3.

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

TestPlasmid and dosea (μg)Titerb on wk p.v.:Challenge methodc% SurvivalAvg survival time (days)
369
I pCBWN
 100.01:801:801:640i.p.100
 100.01:801:801:320Mosq.100
pEGFP (control)
 100.0<1:10<1:10i.p.06.9
 100.0<1:10<1:10Mosq.07.4
IIpCBWN
 100.01:160i.p.100
 10.0, E1:160i.p.100
 1.0, E1:80i.p.100
 0.1, E1:40i.p.100
pEGFP (control)
 100.0<1:10i.p.07.0
  • a Groups of 10 ICR mice were immunized via a single i.m. injection or i.m. followed by electrotransfer (E).

  • b Serum 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.

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