Second doses should in almost all cases be given between 77 and 84 days after the first dose. There are a small number of circumstances when the second dose can be given at a different time interval (eg people receiving medical treatment). People who had their first dose through a GP service should be invited for their second dose through the same GP service. People using the National Booking Service (booking into a vaccination centre or designated community pharmacy) are given their closest available appointment locations. There is an option for the second dose appointment to be booked at a different location, but this applies to the COVID-19 AstraZeneca vaccine only.