FIG 7.
VLPΔVP4-elicited neutralizing antibodies protected mice against lethal viral challenge. (A) In vitro neutralization titers of sera from VLPΔVP4-immunized mice. Groups of female ICR mice were i.p. immunized with VLPΔVP4, VLPfull, or PBS control at week 0 and week 2. At week 4, sera were collected and subjected to neutralization tests against EV71 G082. Each symbol represents an individual mouse, and the horizontal lines indicate the geometric mean values of the groups. (B and C) In vivo challenge experiment. The mice in the VLPΔVP4, VLPfull, and PBS control groups were mated with naive male ICR mice. Neonatal mice born to the immunized dams were i.p. challenged with EV71 MAV-W at 5 days old. All the mice were monitored daily for survival (B) and clinical score (C) for a period of 15 days.