Some vaccines contain live organisms which simulate the disease. The scientifically modified organisms will trigger a good immune response by simulating the disease for a few days in a controlled manner as not to make cat ill.
There are vaccines which contain organisms that have been rendered inactive, combined with other agents to trigger an immune response in your cat’s body.
New and more advanced vaccines called, Recombinant vaccines are protein producing parts of an organism combined with a second organism. The organisms promote a good immune system in your cat’s body to prevent serious illness and reactions to illnesses.
Most important all vaccines have to go through a series of safety tests along with tests to determine effectiveness. The authorities that regulate the feline medicine industry only release vaccines that have been proven safe and effective.
There may be ‘herbal vaccinations’ that people may suggest to you, they have no scientific backing. It is not advisable to use these vaccines because they do not prompt the necessary immune responsibilities. Veterinarians only use regulated and scientifically proven vaccinations.