The USDA Animal and Plant Health Inspection Service has issued a notice to biologics manufacturers requesting information on the efficacy of vaccines against intestinal colonization with Salmonella. The Agency has proposed studies on the application of live vaccines that could be used against designated Salmonella serotypes.  This is of specific importance with respect to contamination of raw chicken carcasses, parts and ground turkey.

The request for information from vaccine manufacturers by the FSIS is reminiscent of the approach adopted by FDA in establishing the Final Rule on Salmonella in Eggs during 2010.  Six months after the Rule was published in the Federal Register, individuals within the Agency were initiating informal conversations with poultry health professionals on the use of Salmonella vaccines.  It was an established practice within the U.S. and E.U. egg industries over a number of years prior to the Rule to administer gene-deleted live attenuated Salmonella Typhimurium vaccines early during the rearing period with administration of inactivated Salmonella Enteritidis emulsion vaccine prior to transfer to laying units.

The FSIS should determine the efficacy of live attenuated Salmonella vaccines in the pre-harvest prevention of a Salmonella contamination of carcasses and parts before finalizing the Salmonella Framework For Raw Poultry Products.  At this stage, the FSIS is still requesting comments with a closure date of January 17, 2025.  The Agency has not indicated how producers will screen flocks for the designated Salmonella serotypes, nor has it indicated what measures are practical to suppress pre-harvest Salmonella infection.

The proposed Salmonella Framework for all poultry products has the potential to disrupt the industry and markedly increase costs. These will be passed on to consumers without having quantified efficacy of suggested measures or benefits through a reduced incidence of chicken and turkey-derived salmonellosis. At the very least a pilot study is indicated.