The three Covid-19 vaccines, that have been approved in the UK, are from Pfizer-BioNTech, the University of Oxford and Astra-Zeneca and Moderna.
The
Pfizer, Oxford and Moderna
vaccines each require two doses and you are not fully vaccinated until a week after your second shot.
But there are many differences between them.
How much immunity they give, how they prevent infection and if any are better than the other.