Immunogenicity and Cross Protection in Mice Afforded by Pandemic H1N1 Live Attenuated Influenza Vaccine Containing Wild-Type Nucleoprotein

Figure 1

Infectious viral titers in eggs at different temperatures. Viruses stocks propagated in eggs at the permissive temperature (33°C) were titrated 3–5 times by end-point dilutions at the permissive or nonpermissive temperatures (26°C and 38°C). The bars represent arithmetic mean virus titers at indicated temperature ± standard deviations (SD) (T-lines). value is shown for the two H1N1 LAIVs being compared at 33°C (Mann–Whitney test). White bars: 26°C (for the ca phenotype); grey bars: 33°C (optimal temperature); black bars: 38°C (for the ts phenotype).