Carbon Monoxide Concentration^* in Exhaled Air, per protocol population, in all subjects and per antibody responder group.

*Mean and percentiles 25%–75%. **Not all subjects returned for 9- and 12-months follow-up visits. Carbon monoxide concentration expressed in ppm. High = Subgroup of subjects with high anti-nicotine antibody levels. Medium = Subgroup of subjects with medium anti-nicotine antibody levels. Low = Subgroup of subjects with low anti-nicotine antibody levels.