Figure 6. Effective control of viral replication by a single dose VLP vaccination.

Groups of mice that received a single intramuscular vaccination with recombinant H5 HA protein or H5 VLPs were intranasally infected with influenza A/Viet Nam/1203/04 (H5N1) virus (50 x MLD₅₀) and sacrificed on day 4 post challenge (n=3). Spleen, lung and brain tissue samples were harvested from individual mice and the homogenates were used for plaque assay to determine virus titers. Data are represented by the mean virus titer (plaque forming unit [pfu] per ml of homogenate) with standard error of mean (SEM). The dashed line indicates the limit of detection (1.7 log₁₀ pfu/ml). * Virus was isolated from one out of three mice.