Volume 13, Number 3—March 2007
Research
Matrix Protein 2 Vaccination and Protection against Influenza Viruses, Including Subtype H5N1
Figure 7
![Results of vaccination with matrix protein 2 (M2)–DNA plus M2-adenovirus (Ad) and challenge with heterologous H5N1 subtype. Mice (10 per group) were vaccinated with A/NP-DNA, M2-DNA, or B/NP-DNA and boosted with matched Ad, as described in the Methods. Seventeen days after Ad boost, mice were challenged with 10× 50% lethal dose (LD50) of SP-83 (H5N1). A random subset pf mice (4/group) were humanely killed on day 5, and their lungs were assayed for virus titer, as described in the Methods. A). Re](/eid/images/06-1125-F7.jpg)
Figure 7. Results of vaccination with matrix protein 2 (M2)–DNA plus M2-adenovirus (Ad) and challenge with heterologous H5N1 subtype. Mice (10 per group) were vaccinated with A/NP-DNA, M2-DNA, or B/NP-DNA and boosted with matched Ad, as described in the Methods. Seventeen days after Ad boost, mice were challenged with 10× 50% lethal dose (LD50) of SP-83 (H5N1). A random subset pf mice (4/group) were humanely killed on day 5, and their lungs were assayed for virus titer, as described in the Methods. A). Remaining mice were monitored for weight loss (B) and survival (C). The cumulative survival rates for A/NP and M2 immune mice were significantly higher than those for B/NP-immune mice but did not differ from each other significantly (p<0.001, log-rank, Holm-Sidak pairwise comparison: p<0.05 comparing B/NP with A/NP or M2 groups, p≥0.05 comparing A/NP and M2 groups). *Lung virus titers in A/NP- and M2-immune mice were significantly lower than in B/NP-immune mice but did not differ from each other significantly (p = 0.004, analysis of variance. Holm-Sidak pairwise comparison: p<0.05 comparing B/NP with A/NP or M2 groups, p≥0.05 comparing A/NP and M2 groups). SARS, severe acute respiratory syndrome; IFN-γ, interferon-γ.