ATHENS – With indicators showing that COVID-19 is gradually receding as vaccinations pick up, Greece is now welcoming tourists with proof they've been inoculated or free of the virus, hoping for a big summer boom.

International air traffic is picking up, Airbnb said bookings are jumping and people are roaring to get out of lockdowns and head to countries like Greece for sun, sand, surf and forget the terror that's still gripping the world.

Greece took the lead in inviting them after convincing a reluctant European Union to later institute certificates of vaccination for travelers to use to avoid quarantines when they visit other countries.

Greece  opened to the EU, United States, Israel, United Arab Emirates and a handful of countries where vaccines were working, as well as the United Kingdom and could be at the forefront of a vanguard year of recovery.

Now Greece is using a multimillion-euro campaign to lure travelers as a destination, surveys showing it's already a favored hot spot this year although the US said it wasn't safe and the UK had it off limits.

“We are opening our tourist industry to the world,” Tourism Minister Haris Theoharis said at an outdoor news conference held outside the backdrop of the Temple of Poseidon on Cape Sounio, the Reuters news agency said.

Promotional videos telling stressed-out British office workers and others in need of a break that “All you want is Greece” will be shown in key markets, vaunting the country’s beaches, historical sites and tavernas, the report  said.

Tourism is Greece's biggest revenue engine, bringing is as much as 18-20 percent of the annual Gross Domestic Product (GDP) of 165.27 billion euros ($200.3 billion) and had employed close to one million people before the pandemic hit.

Until COVID-19 arrived in 2020, the country was on a run of record years and expects a modest comeback although there are signs it could be bigger with more people being vaccinated around the world and allowed to travel.

The economy shrank 8 percent in 2020 during two lockdowns aimed at slowing the spread of the Coronavirus that closed non-essential businesses for months at a time, idling hundreds of thousands of workers, including in tourism.

Tourism revenues plummeted to only 4 billion euros ($4.85 billion) in 2020 from 18 billion euros ($21.82 billion) in the record year of 2019, but analysts are unsure how much they will go up this year, the spring season only now underway.

Theoharis, back after a series of foreign visits, including to the US and UK to promote Greece, didn't know either, saying only “It will be better than last year,” when most tourism businesses were shuttered.

Travelers returning to Germany and Britain still have to quarantine, meaning visitor numbers from two of Greece’s key markets are likely to be limited for the moment. But Theoharis said this week he was optimistic Britain would put Greece on its “green list” soon of its designated safe countries.