Boris Johnson has said he is "very confident" the UK's use of India-produced jabs won't stop Britons travelling abroad - as Germany's Angela Merkel offered hope of quarantine-free trips for those who are double-jabbed.
Better news was given to Britons hoping to travel to Europe for a holiday or to reunite with friends and family this summer, after Mrs Merkel had previously been more hardline on EU restrictions on those coming from the UK.
It was reported this week that the German chancellor had been hoping to encourage EU countries to ban British travellers from the bloc regardless of whether or not they have had a vaccine.
She was said to have wanted to designate Britain as a "country of concern" due to the spread of the Delta variant in the UK.
But, speaking following talks with Mr Johnson at the prime minister's official country retreat of Chequers, Mrs Merkel said: "We have adopted certain protective measures when we were not as yet so familiar with the Delta variant.
"We now see that the share of those with the Delta variant in Germany is increasing very rapidly.
"We are reviewing continuously our travel restrictions and we think that in the foreseeable future those who have received double jabs will then... be able to travel again without going into quarantine."
Meanwhile, the prime minister played down concerns that millions of Britons could miss out on foreign trips this summer because their COVID jabs aren't recognised by the EU's drug regulator, the European Medicines Agency (EMA).
It had been reported that up to five million Britons would not qualify for the EU's vaccine passport scheme because the AstraZeneca shots they received were manufactured in India.
But Mr Johnson said: "I see no reason at all why the MHRA-approved vaccines should not be recognised as part of the vaccine passports.
"I am very confident that will not prove to be a problem."
Downing Street earlier said it would work with the European Commission on mutual recognition of vaccine certification and stressed that all AstraZeneca vaccines used in the UK are the "same product and subject to regular checks".
The UK's Medicines and Healthcare products Regulatory Agency (MHRA) has shared its assessment of the vaccines with the EMA to assist the approvals process, according to a Number 10 spokesman.
"They're the same product which has been authorised and checked for safety and quality by our MHRA," the spokesman said.
"They've shared their inspection report with the EMA."
According to reports, up to five million doses of the India-produced AstraZeneca vaccine - a version known as Covishield - have been administered in the UK and are identifiable by the vaccine batch numbers 4120Z001, 4120Z002, and 4120Z003.
But nine European countries - Austria, Germany, Slovenia, Greece, Iceland, Ireland, Spain, Estonia and Switzerland - are said to be ready to accept the India-made version of the AstraZeneca jab.
A European Commission spokesman said individual member states could allow entry for people vaccinated with jabs on the World Health Organization's list of vaccines approved for emergency use.
"This is the case for Covishield which is not authorised for placing on the market in the EU," the spokesman added.
During her visit, her last before she steps down from power, Mrs Merkel also addressed a virtual meeting of the Cabinet, the first foreign leader to do so since Bill Clinton in 1997.
The German chancellor and Mr Johnson were due to have a working lunch of English asparagus tart, Oxfordshire beef fillet and baked custard tart.