FIG. 4.

Protection of hamsters with HuMAbs in the primary challenge model. Hamsters were treated with CDA1 (50 mg/kg/day) alone or in combination with MDX1388 (10 to 50 mg/kg/day) for 4 days beginning 3 days prior to spore administration. Clindamycin (10 mg/kg) was injected intraperitoneally 24 h prior to spore challenge. Spores were delivered orogastrically, and animals were observed for up to 11 days. A total of six experiments were performed, and a summary of all hamster primary challenge experiments using percent survival at either 2 or >5 days after challenge is shown. The fractions above the bar graphs represent the numbers of surviving animals (numerators) and the total numbers of animals (denominators), with P values indicated (the Fisher exact test). NS, not significant.