Covid-19: vaccines and medicines


During the current pandemic we have heard from lots of scientists and health care professionals about the need to find vaccines and medicines to tackle COVID-19.

Here is a quick summary of the differences between vaccines and medicines. We focus on who they are for and how they work.


A vaccine is for people in general good health to PREVENT them from becoming seriously unwell. Each vaccine protects us from getting a specific disease.

Vaccines contain a dead or altered version of the virus or bacteria (collectively known as pathogens), which is introduced into our bodies, usually by an injection (e.g. adult influenza vaccine), drops into the mouth (e.g. polio vaccine) or a spray into the nose (e.g. children’s influenza vaccine).

These dead or altered pathogens carry a specific antigen. This causes our immune system to respond by producing antibodies, which target and attach to the antigen.

If the live pathogen enters our bodies in future, our bodies recognise the antigen and can quickly make large quantities of antibodies to defend us from the disease.


A medicine is a substance that TREATS people who are suffering from pain or a disease. A medicine works by affecting chemical reactions in the body or by killing pathogens.

All medicines need to go through clinical trials to check they are safe to use and that they work effectively.