Fig 1. Vaccination strategy and schedule.

Two cohorts of mice were vaccinated with A/California/07/2009 (A/Cal09, H1N1) and A/Hong Kong/1/1968 (A/HK68, H3N2) influenza virus rHA, respectively. A negative control group was included, consisting of vaccination with Addavax alone; the infection group consisted of intranasal infection with of same influenza viral strains at day 0 for both cohorts. rHA vaccinations (Vax) were delivered three weeks apart, with or without Addavax adjuvant as indicated. Individual mice were bled at pre-vaccination (day 0), and at 21, 42, and 63 days post vaccination, and sacrificed at day 63 for collection of spleen and bone marrow cells.