FIG 6.
Protection conferred by the ca vaccines against homologous and heterologous challenge in mice. Mice were intranasally inoculated with either L-15 (mock) or 1 or 2 doses of 106 TCID50/mouse of AA ca, Jap/57 ca, mal/78 ca, or sw/06 ca vaccine and challenged 1 month following the last vaccine administration with 105 TCID50/mouse of the indicated challenge virus. Virus titers were determined on day 3 postchallenge. Levels of replication of the indicated challenge viruses in the upper (A) or lower (B) respiratory tracts of mice that were challenged following 1 dose of the indicated ca vaccine. Levels of replication of the indicated challenge viruses in the upper (C) or lower (D) respiratory tracts of mice that were challenged following 2 doses of the indicated ca vaccine. Homologous challenge is indicated by a arrows. The dashed horizontal line represents the lower limit of detection.