Figure 2. Correlation of survival of passively immunized mice with neutralizing antibody titer following challenge with wild-type H5N1 virus.

Data points represent the mean % of surviving animals 14 days following lethal challenge of CD1 mice which had received immune sera from (A) CD1 mice, (B) guinea pigs or (C) humans. Reciprocal neutralizing antibody titers shown are extrapolated from titers measured 2 h prior to challenge. All individual mice receiving mouse immune sera of titer ≥1∶18 or guinea pig immune sera of titer ≥1∶37 were protected from disease; these animals are omitted from the figure to allow better resolution of lower titers.