FIG 5.
PANENZA vaccine was treated with 100 μg/ml RNase at 37°C for 30 min. RNase-treated vaccine (3 μg of HA) was injected intraperitoneally alone (RNase/Vac; ▲) or in combination with 50 μg of imiquimod (RNase/Vac+imq; ⧫) 3 days prior to virus infection. Mice in the control group received the same volume of PBS (□). The mice were then infected intranasally with 10 times the mouse LD50 of mouse-adapted A(H1N1)pdm09 virus. Survival was observed for 14 days after virus infection. **, P < 0.01 (compared with the RNase-treated vaccine or PBS group). n = 6 per group.