It is likely that new viral diseases may continue to emerge in companion animals. It is more likely that genetic or antigenic virus variants or geographically translocated viruses may emerge or re-emerge in companion animals, however. This latter possibility represents the greater risk. Because this represents an ongoing threat, research and development should continue to maximize broad efficacy and effectiveness in addition to safety. To achieve these goals, the research and development effort should evaluate newer available technologies that may also reduce any barriers to use and availability.