MIAMI (CBSMiami/AP/CNN) – Miami International Airport, along with other airports across the country, are receiving fully vaccinated foreign travelers on Monday, ending restrictions that had barred much of the world from entering the United States for as long as 21 months.

Starting Monday, the U.S. lifted restrictions on travel from more than 30 countries including Mexico, Canada and most of Europe, as long as the travelers has proof of vaccination and a negative COVID-19 test.

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Those crossing land borders from Mexico or Canada will require proof of vaccination but no test. The vaccinations must be approved for emergency use by the World Health Organization, not just those in use in the U.S. That’s a relief for many in Canada, where the AstraZeneca vaccine is widely used.

Other approved vaccines are:  Janssen/Johnson & Johnson, Pfizer-BioNTech, Moderna, Covaxin, Covishield, BIBP/Sinopharm and Sinovac.

Millions of people around the world who were vaccinated with Russia’s Sputnik V, China’s CanSino or others not OK’d by the WHO won’t be able to travel to the U.S.

American citizens and permanent residents were always allowed to enter the U.S., but the travel bans grounded tourists, thwarted business travelers and often separated families.

Airlines are preparing for a surge in activity. Data from travel and analytics firm Cirium showed airlines are increasing flights between the United Kingdom and the U.S. by 21% this month over last month.

In a sign of the huge importance of trans-Atlantic travel for airlines, British Airways and Virgin Atlantic celebrated the reopening by synchronizing the departures of their early-morning flights to New York on parallel runways at London’s Heathrow Airport.

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New York, Miami and Los Angeles may see some of the most significant influxes of international visitors. They are travel app Hopper’s top destinations for foreign travelers this holiday season.

The moves come as the U.S. has seen its COVID-19 outlook improve dramatically in recent weeks since the summer delta variant surge that pushed hospitals to the brink in many locations.

Children under 18 are exempt from the vaccination requirement. The CDC has the full slate of air travel requirements on its website.

People are considered “fully vaccinated” by the CDC two weeks after their second dose in a two-dose series, or two weeks after a single-dose vaccine.

Mixed-dose vaccinations will also be accepted. Some participants in vaccine trials will also be considered fully vaccinated.

Many airlines have mobile apps and portals on their websites where vaccination and testing information can be processed digitally.

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(© Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press and CNN contributed to this report.) Team