Fig 5.

Individual (log₂) pre- and postchallenge HI titers for groups in experiments I (A) and II (B). Birds in experiment I were vaccinated with a single dose at 7 weeks of age and challenged at 10 weeks of age. Serum was taken from survivors at 2 weeks p.c. Birds in experiment II received a single vaccination at 2 weeks of age and were challenged at 5 weeks of age. Serum was taken from survivors at 2 weeks p.c. Statistical significance between mean titers was determined by ANOVA using Tukey's multiple-comparison test (P < 0.05).