Vaccine prevention can only be carried out when the cat is completely healthy, even if it is just a slight runny nose, because if the cat's resistance is weak, it is easy to have a violent reaction to a weak virus such as the vaccine. After deworming the cat, it is best not to inject the vaccine immediately. It is recommended to wait a week before injecting. Pregnant female cats and kittens under 2 months old are not suitable for vaccination, as they can easily lead to miscarriage and illness.