Figure 4: Survival rates of chickens after challenge with A/chicken/ Yamaguchi/7/2004 (H5N1). Four-week-old chickens were immunized intramuscularly three times (at weeks 0, 2, and 4) with 250 μg of HANA- M1 VLP formulated in adjuvant. Three weeks later, all of the vaccinated chickens were challenged intranasally with A/chicken/Yamaguchi/7/2004 (H5N1). Symbols: 3 immunized chickens after challenge with A/chicken/ Yamaguchi/7/2004 (H5N1) (black diamond); 3 non-immunized chickens after challenge with A/chicken/Yamaguchi/7/ 2004 (H5N1) (black squares).