One way is to look at the powder package in the vaccine. When you get the vaccine normally, the powder will be in a lumpy state, and the lumps can shake up and down. This means that the vaccine can be used normally. When the vaccine powder spreads, it means it has expired. ​​​​​​

However, many people say that this method is not necessarily very reliable, and whether the vaccine is effective cannot be seen with the eyes. When purchasing vaccines online, be sure to check their authenticity.

It is best to go to a regular veterinary hospital or pet clinic to vaccinate cats with Sanlian. Regular hospitals will issue vaccination certificates to cats. The certificate will have the vaccine the cat has received, and you can check the authenticity of the vaccine.