Synonyms of 'vaccine'
If you have an injection, a doctor or nurse puts a medicine into your body using a device with a needle called a syringe.
They gave me an injection to help me sleep.
Thesaurus for vaccine from the Collins English Thesaurus
A vaccine is a substance containing a harmless form of the germs that cause a particular disease. It is given to people, usually by injection , to prevent them getting that disease.