For the active immunisation of cats and kittens to reduce mortality and clinical signs caused by feline rhinotracheitis virus; to reduce clinical signs due to feline calicivirus; to prevent mortality and clinical signs and reduce the adverse effects on the immune system caused by feline panleucopenia virus infection. For the prevention of persistent viraemia associated with feline leukaemia virus infection. The onset of immunity is from two weeks after the second vaccination. The duration of immunity is at least one year for all four antigens.