FIG 7.

Pathogenicity of D/5920 in Ifnar1^−/− mice. Ifnar1^−/− mice were infected with 10⁵ TCID₅₀ of D/5920. Clinical signs were recorded daily during 14 days. (A) Weight was recorded every 2 days for noninfected and infected mice. (B) At 4 dpi, 4 infected mice were euthanized, and different organs were collected. Virus titers were determined using the TCID₅₀ method and are expressed in log₁₀ of TCID₅₀/g of tissue. The dotted line represents the positivity threshold (1.5 log₁₀ TCDI₅₀/g of organ). KO, knockout.