How Do Covid-19 Vaccines Work?
To understand how COVID-19 vaccines work, it helps to first look at how our bodies fight illness.
When germs, such as the virus that causes COVID-19, invade our bodies, they attack and multiply. This invasion, called an infection, is what causes illness. Our immune system uses several tools to fight infection.
Blood contains red cells, which carry oxygen to tissues and organs, and white or immune cells, which fight infection.
Different types of white blood cells fight infection in different ways: