The approved pilot projects are listed on the “Pilot Projects: Salmonella Control Strategies” page of the FSIS website, where a summary report of the data from these pilots can also be viewed. The data collected during the pilot were analyzed by FSIS to determine whether they support changes to existing FSIS Salmonella control strategies.

Modified live Salmonella vaccines are used to reduce Salmonella colonization in poultry. These vaccine strains are not foodborne pathogens, making them a valuable preharvest tool for controlling wild-type Salmonella. FSIS is able to identify vaccine strains isolated from raw poultry products through the use of whole genome sequencing (WGS).

FSIS examined Salmonella detection and serotype data from flocks vaccinated with a modified live Salmonella vaccine at pre- and post-intervention points in the participating slaughter establishments. The findings show that vaccine strains can occasionally be found in raw poultry products even when the vaccine is used as directed on the label.

FSIS’ current policy to count such strains as a positive result in performance categorization may discourage use of vaccination as a tool to control Salmonella. To remove barriers that inhibit the use of these pre-harvest interventions, FSIS intends to exclude current commercial vaccine subtypes confirmed in FSIS raw poultry samples from the calculation used to categorize establishments under the raw poultry Salmonella performance standards. This change will commence with categorizations calculated on or after April 1, 2024. FSIS will implement the change on April 1, 2024, unless the agency receives substantive comments that warrant further review. Comments can be submitted on or before March 30, 2024 to www.regulations.gov.