This depends on the type of vaccine the cat receives. Some vaccines require two injections, and some vaccines require three injections. Kittens should receive the first vaccine when they are 3-4 months old, and then receive the second and third shots according to the time prescribed by the drug. After that, it is best for cats to receive regular vaccinations every year. Cat vaccines can prevent the occurrence of many diseases and viruses, form antibodies in cats, and extend the life of cats.