Campylobacter jejuni is the most common bacterial cause of diarrhea in many developed countries, with an estimated 1.5 million cases in the U.S. each year. It is also a common cause of travelers’ diarrhea. In developing countries infection in early childhood is nearly universal. Worldwide, there are 400 million cases per year. Campylobacter species are also associated with Guillain-Barré syndrome and reactive arthritis. These bacteria are frequently found in the intestinal tract of animals, especially birds. Transmission is generally food-borne and occurs through consumption of contaminated water and raw milk or undercooked poultry and other meats.
Immunity to Campylobacter appears to be strain-specific and the antigens conferring immunity are not well understood. A candidate vaccine consisting of formalin-killed whole bacteria combined with LT as a mucosal adjuvant has been developed by the Navy Medical Research Institute (USA) and shown to provide 87 percent protection against intestinal colonization in pre-clinical animal studies. Similarly an injectable recombinant protein vaccine, designated ACE 393, has also been shown to reduce colonization in animals. The recombinant protein vaccine has moved into Phase I clinical studies in man and has been shown to induce strong anti-Campylobacter antibody responses in all subjects, to date. Other vaccine formulations are being developed, including a multivalent vaccine expressing antigens from Campylobacter, Shigella species, and ETEC, but this approach is only in the early animal testing stage.
Division of Foodborne, Bacterial and Mycotic Diseases
Food Safety and Inspection Service
Here is a link to information about participating in vaccine studies for Travelers' Diarrhea at the CIR.