Figure 5. Maintenance of long-lasting protection against lethal dose challenge in vaccinated mice.

A24Tg mice were immunized i.n. three times (A), s.c. three times or s.c. twice followed by i.n. (B) with PA_130–138, PB1_430–438 and PB2_549–557 peptides at 7 to 9 days intervals, unimmunized mice were administrated with PBS. Eight weeks after the final immunization, mice were challenged i.n. with lethal dose of A/HK483 virus, and the survival and the body weight were monitored for 14 days.