. Enteritidis counts in individual chickens after oral or intravenous challenge. Left panel, S. Enteritidis counts in the liver 4 days following oral challenge. “w” indicates age of individual chickens at the time of infection. Right panel, S. Enteritidis counts in the liver 4 days following intravenous challenge. * significantly different from non-vaccinated chickens, # significantly different from orally vaccinated chicken by ANOVA at P < 0.05.