The first dose of the COVID vaccine acts as an important immune response primer, the second dose is needed to boost your body’s immune response to the virus, providing the best protection for you.

The booster is an additional vaccine dose those who have previously received two doses of a COVID-19 vaccine. It ensure continued protection for those most at risk from COVID-19.

The third dose is for people with severely weakened immune systems -  it is not a booster, but a third dose to ensure that they have the same protection given by two doses for those with normal immune systems. 

Click to find out information about the COVID vaccine doses.