
An injection, also known as a shot, is putting liquid into the body, usually with a needle and a syringe. There are many different kinds of injections, such as:
Injections can be used to prevent illness or to give medicine. When in an emergency an intravenous injection can not be done, it can be put into a bone. This is done after drilling into the bone and it is very painful.
Injections that prevent illness put a dead or weakened version of the virus they want to prevent into the body. The body then 'remembers' the virus to make future encounters of the virus easier to manage.