Fig. 3: Protective efficacy of mutant influenza B viruses in ferrets.
From: Development of broadly protective influenza B vaccines
a Immunization and challenge scheme. Ferrets were immunized three times with the indicated recombinant HA protein. Five weeks after the third immunization, ferrets were challenged with 106 pfu of wild-type Phuket/Yam or Wash/Vic virus. (Created in BioRender, Neumann, G (2024) https://BioRender.com/e49u244) (b) Ferret sera were collected 3 weeks after the third immunization (i.e., two weeks before challenge), and tested against Phuket/Yam, Wash/Vic, Phuket/Yam-Mut, and Wash/Vic-Mut viruses. c Virus titers in nasal swabs after challenge with wild-type Wash/Vic virus. d Virus titers in nasal swabs after challenge with wild-type Phuket/Yam virus. The values presented are the averages ±SD. P values were calculated by using a two-way ANOVA with multiple comparisons. Black asterisks indicate statistically significant differences between the PBS-treated control group and immunized animals. Blue asterisks (c) indicate statistically significant differences between the Phuket/Yam rHA-immunized group and any of the other immunized groups. Red asterisks (d) indicate statistically significant differences between the Wash/Vic rHA-immunized group and any of the other immunized groups. *P < 0.1; **P < 0.01; ***P < 0.001; ****P < 0.0001.
