© Steve Parsons/PASome countries, including Croatia and Austria, have introduced a time limit for the validity of the coronavirus jab.
Travellers from England who have had a booster or third dose of vaccine will be able to demonstrate their vaccine status through the NHS Covid pass, which will allow them to travel to countries requiring proof for entry, ministers have announced.
Israel, Croatia and Austria are among countries that have already introduced a time limit for the Covid-19 vaccine to be valid for quarantine-free travel.
However, it will not be necessary to show evidence of a booster for travel into England at this time, the Department of Health and Social Care said.
Evidence suggests immunity provided by two doses of any of the approved Covid vaccines has waned six months after the second jab.
Booster and third doses will not be added to the domestic Covid pass as it is not a current requirement for individuals to receive booster doses to qualify as fully vaccinated.
More than 13m booster and third jabs have been administered in the UK, providing those eligible with maximum protection as winter approaches.
The health and social care secretary, Sajid Javid, said: "We want to make it as easy as possible for people to show their vaccine status if they are travelling abroad.
"This update to the NHS Covid pass will mean people can have their complete medical picture at their fingertips if they are going on holiday or seeing loved ones overseas.
"Getting a top-up jab is our best defence against this virus and I urge all those who are eligible to come forward and get boosted."
The NHS Covid pass enables people to demonstrate their Covid-19 status when travelling abroad or when visiting organisations who have opted to use the domestic certification process.
Booster and third doses will show up automatically in the digital Covid pass and will be visible from midday on Friday for users in England but will not immediately be available via the Covid pass letter service, which will be updated in due course.
The booster vaccine will appear on the Covid pass in Wales from 29 November.
However, evidence of a booster vaccine is not needed to enter venues in Wales that require a Covid pass for entry. Evidence of two vaccinations or a negative lateral flow test in the last 48 hours remain the requirement.
The announcement does not cover Scotland and Northern Ireland.
Comment: The categories of segregation are becoming more complex every day. This is by design, as a population kept gaslit by ever-shifting requirements is too busy trying not run afoul of the 'rules' to notice the bars of the cage they are being herded into.