Four (4) out of six (6) mice inoculated with wild-type vector UC72, succumbed to infection by day 10; while two (2) out of six (6) mice infected with UC75 (14.5% knockdown) also died by 12 d.p.i. Macroscopically the lungs of mice infected with the UC71 Srb1 silenced strain, showed almost no signs of infection and appeared pink and spongy. Here, SCARB1 is linked to infection.