Notice of CDC's discontinuation of investigational pentavalent (ABCDE) botulinum toxoid vaccine for workers at risk for occupational exposure to botulinum toxins.

Effective November 30, 2011, CDC will no longer provide investigational pentavalent (ABCDE) botulinum toxoid (PBT) for vaccination of workers at risk for occupational exposure to botulinum serotypes A, B, C, D, and E. This change might affect persons working in public health laboratories, research facilities, and manufacturing institutions who work with botulinum toxin or neurotoxin-producing species of Clostridium. CDC's decision is based on an assessment of the available data, which indicate a decline in immunogenicity of some of the toxin serotypes. The occurrence of moderate local reactions related to annual booster doses also has increased, which was noted in the 1990s at the U.S. Army Medical Research Institute for Infectious Diseases and resulted in a change in boosting from an annual requirement to only boosting when antibody titers have declined significantly. Additionally, the PBT was manufactured more than 30 years ago. CDC, therefore, has decided not to continue offering this investigational product.