Vaccination continues to be a major tool for controlling feline infectious diseases, but numerous factors present both challenges and opportunities for maintaining and expanding the market for veterinary biologicals. Developing novel vaccines is one approach, but in most cases the market for such products will be restricted to niche populations; the comparatively smaller quantity of vaccines sold may be offset somewhat if available from a limited number of manufacturers. A second approach is to produce better formulations of existing vaccines; such products would be applicable to larger populations of cats and have greater sales potential. But veterinarians must be convinced of the improved product's superiority for it to be successful in the marketplace. To ensure that high-quality, useful and necessary vaccines reach the marketplace, communication between veterinarians, the manufacturers of biologicals, and regulatory agencies must be enhanced.