Dose-response of anti-LcrV serum titers in VSV-ssLcrV1 immunized mice. Mice in five different groups were immunized intramuscularly (IM) on day 0 with 105, 106, 107, 108 and 109 pfu of VSV-ssLcrV1. Blood was collected, by retro-orbital bleeding, on days 28 and 53 post inoculation. Serum samples were pooled and total IgG titers, specific to LcrV, were determined at the indicated days using ELISA.