FIG 2.

Virus loads in nasal swabs and BALF samples of contact and principal pigs infected with endemic and different reassortant H3N2 viruses. (A) Virus titers in BALF samples of infected and contact pigs. (B) Virus titers in nasal swabs of infected pigs. (C) Virus titers in nasal swabs of contact pigs. All animals were positive for virus isolation at the time points shown unless otherwise indicated (e.g., 2/4 means 2 of 4 animals were positive). The dotted lines represent the limits of detection. The error bars represent SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001.