The boss of travel giant Tui is “optimistic” families will enjoy foreign holidays this summer.
Friedrich Joussen said mass vaccine scheme here and in Europe were key to the return of breaks abroad.
It came as he revealed booming demand for getaways, with 2.8 million bookings last month.
Tui expects to operate up to 75% of its normal summer schedule.
Britons will be allowed to travel abroad from May 17 under the road map to easing Covid restrictions.
Mr Joussen told the BBC: “We are still confident we will have a decent summer.
“All medical advice we are getting says existing vaccines are working with existing variants.”
He added he expected some countries to ask travellers to prove they had been vaccinated before they can fly.
Transport Secretary Grant Shapps recently said tourists will have to take tests before leaving and on arrival –even from low-risk “green” countries.
It comes amid criticism of how much travellers are having to pay for PCR tests, with No10 threatening to crack down on “profiteering” firms.
UK companies charge around £141 for each check for overseas travel, more than twice as much as other European countries.
Ministers want the bill cut to nearer £60 and there is also criticism that VAT is charged on tests.
Experts fear the cost will price many families out of summer hols.
Mr Joussen said: “The cheaper it gets, the better it works and the less harmful it is for the general economy.”
Last week, the boss of easyJet called for families to be able to enjoy test-free holidays to most EU countries.
Johan Lundgren also demanded ministers to quickly publish the list of low-risk nations.
He said: “I would expect almost all major European countries to be in that category.”
Meanwhile, trade body the World Travel and Tourism Council says the industry globally has seen income slump by £2.9trillion, leaving more than 62 million people in the sector out of work.
The industry body is pressing for international travel to resume in June to stem further job losses.
Mr Shapps recently scrapped his advice not to book foreign holidays.
He said: “For the first time I think there is light at the end of the tunnel and we’ll be able to restart international travel, including cruises by the way, in a safe and secure way.”
Mark Tanzer, head of travel trade body ABTA, has called the Government’s plan for reopening international travel “overcautious”.
He told Travel Weekly: “We’ve said to ministers ‘waiting until the day before May 17 before telling us means travel won’t restart on May 17.’”
He added; “It talks about vaccination levels, the presence of variants and so forth, but there is no guidance as to how high those thresholds will be set or which countries will come into that category.”
It comes amid pressure on ministers to tackle lengthy border checks at UK airports in time for the restart of summer holidays abroad.
There have been reports of people left queuing at passport control for two to three hours, or in some cases up to seven hours.