Phase II safety and immunogenicity study of type F botulinum toxoid in adult volunteers.

An aluminum hydroxide (alum)-adsorbed, purified, botulinum F toxoid (Bot F) vaccine was manufactured to be administered as a stand-alone monovalent vaccine or to be added to the current botulinum pentavalent toxoid vaccine to make a hexavalent vaccine. We conducted a phase II trial of the Bot F vaccine over 3 years in 144 healthy adult volunteers to identify one of three vaccination schedules that was safe and maximally immunogenic for adult volunteers. We vaccinated 116 volunteers 1-3 times with Bot vaccine, and 28 volunteers 1-3 times with a licensed, alum-adsorbed hepatitis B vaccine (Engerix-B) as a reaction control group.