Fig 1.

Vaccine-induced IgM helps to protect mice against pathogenic RABV challenge. sIgM^−/− or wild-type control mice were immunized i.m. with 10⁶ FFU of rRABV-ΔM or PBS alone and then challenged 3 days later i.m. with 10⁵ FFU of pathogenic RABV CVS-N2c. Survivorship (A) and weights (B) were measured and recorded for 27 days postchallenge. Data shown are a combination of 2 independent experiments consisting of 5 mice per experiment (total n = 10 mice/group). Kaplan-Meier survival curves were analyzed by the log-rank test (***, P < 0.001; **, P = 0.001 to 0.01; *, P = 0.01 to 0.05). Symbols for control (PBS-immunized) sIgM^−/− mice were shifted slightly in panel A for clarity. Crosses in panel B indicate the days when the last mice in a specific group were to be euthanized.