The first vaccinations should be given to kittens from around eight to nine weeks of age. This timing is important – too early and the antibodies they receive from their mother will interfere with the immune response to the vaccine, preventing it from working properly. Too late and kittens will be left susceptible to infection. Two vaccines are usually needed – three to four weeks apart. Giving vaccines twice ensures a satisfactory level of immunity. A booster vaccine should be given one year later to keep immunity levels high. Further needs should be discussed with your vet.