Florida will require proof of residence for those getting a Covid shot in a push to thwart so-called "vaccine tourism," a move experts say could also leave thousands of undocumented immigrants, homeless and low-income people in the lurch.

The decision came after residents of other states and even people from abroad were reportedly arriving in Florida -- which currently vaccinates anyone over age 65 -- with an aim of gaining easier access to immunization.

While the state has administered more than 1.3 million doses, the process has been slow and chaotic.

In a public advisory issued Thursday, Florida's Surgeon General Scott Rivkees indicated that applicants must show proof of residence -- such as driver's license, utility bill or letter from a bank -- in order to be immunized.

Apart from "snowbirds," people from northern climes such as New England and Canada who head to the southern state for the winter, Florida is home to a substantial population of immigrants -- with one in five residents born abroad.

A study from August by the American Immigration Council showed that around 775,000 undocumented migrants live in Florida, representing about 18 percent of the immigrant population.

Unable to obtain a Florida driver's license, many register for public services under a third party's name.

"It's really unfortunate that the consequence of these new regulations is going to exclude some of the most vulnerable people in our community who are undocumented people," said Lily Ostrer, a physician at Jackson Memorial Hospital.

This creates "a cruel and deliberate barrier," said Thomas Kennedy, Florida coordinator for the nonprofit United We Dream.

It not only hinders many Florida residents "including undocumented immigrants, but also people who lack access to housing or folks who are very low income from being able to access documentation to get them access to the vaccine right now," he said.

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