Vaccination protects cats from potentially fatal infectious diseases, with welfare benefits that far outweigh the minimal stress of the vaccination procedure itself.
Vaccination prevents diseases causing significant acute and chronic suffering. Cat flu causes painful oral ulcers, respiratory distress, and chronic herpesvirus shedding that affects quality of life for years after infection. FeLV causes a slow, progressive fatal illness. The welfare benefit of vaccination far exceeds the brief discomfort of injection. Annual health checks alongside vaccination provide additional welfare benefit through early disease detection.