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.
Now more details about the vaccine have been published on the Public Health England website including information on the dose, the interval between first and second jab, the storage temperature and whether people who receive the jab will need to be observed afterwards.
The jab needs to be stored at -25C to -15C, which is not quite as cold as the ultra low temperature needed for the storage of the Pfizer vaccine, which needs to be stored at -80C to -60C.
Once it has been thawed it can be stored for 2C to 8C for up to 30 days, giving it a slightly longer shelf life than the Pfizer jab which can only be stored for five days after it has been thawed.
The Oxford/AstraZeneca vaccine does not need to be frozen and can be stored at 2C to 8C for six months or “until expiry”.
The minimum interval between first and second dose of the Moderna vaccine is 28 days, the same as the AstraZeneca jab.
And patients who receive the Moderna jab will need to wait at the vaccination centre and be observed for a period of 15 minutes after they receive the vaccine.
This is the same as the requirement for the Pfizer vaccine.
Those who receive the Oxford/AstraZeneca vaccine do not need observation but they are advised not to drive for 15 minutes after the jab.