People who receive a Moderna Covid-19 jab will be asked to wait for 15 minutes of observation after they receive their vaccine.
Details about the vaccine have been published by the Government as it prepares for the vaccine to be rolled out across England.
The Department of Health and Social Care reiterated that the jab will be rolled out from mid-April after first doses have already been delivered in Wales and Scotland.
A 24-year-old carer from Wales was the first Briton to receive the jab last week.
Elle Taylor, from Ammanford, got the jab at the West Wales General Hospital in Carmarthen on April 7.