The British Virgin Islands are part of a rising number of Caribbean destinations that attract vaccinated travelers — while proving less attractive to unvaccinated people.

Along with Barbados and St. Lucia, the British Virgin Islands allow unvaccinated travelers to enter only if they quarantine for a certain time. Data shows few are willing to do so, especially when they have other options in the Caribbean that don’t require quarantines or vaccine certificates.

The relative strictness or leniency of entrance requirements in the Caribbean is reshaping travel trends in the region. Unvaccinated travelers are gravitating to the islands that will let them in, while the vaccinated want places that keep the unimmunized out.

At least seven Caribbean nations and territories have announced mandatory vaccination policies for incoming adult travelers — Anguilla, Grenada, St. Barts, St. Kitts and Nevis, Trinidad and Tobago, Turks and Caicos, as well as the Cayman Islands.

The Cayman Islands plan to admit vaccinated travelers from Sept. 9 to Oct. 13 during the third phase of its structured reopening. Thereafter, the territory may let unvaccinated travelers enter if they quarantine for 14 days.

Safety is cited as the main reason behind the requirement, but such policies may also be good for business.

Marketing technology company Zeta Global analyzed site traffic to the main tourism websites of several islands after they announced vaccinated-only policies, said Eric Bamberger, senior vice president of hospitality at Zeta Global.

Following the announcements, travel interest increased to all of them: Grenada — up 25%; St. Kitts and Nevis — up 26%; Cayman Islands — up 44%; Anguilla — up 59%  

The data showed two trends emerging in the Caribbean, said Bamberger.

“People have more interest in traveling to islands where there are vaccination protocols in place,” he said. “And their interest among other islands

without vaccination protocols is waning.” 

Turks and Caicos prepared itself for mixed feedback when it announced its policy earlier this month, said Jamell R. Robinson, the islands’ minister of health and human services.

However, “we have received a hugely encouraging overall response from new and existing visitors,” he said. “We anticipate it will have a long-term positive impact on bookings.”

In contrast to islands with relatively strict policies, places such as the Dominican Republic, Jamaica, the Bahamas and the U.S. Virgin Islands have entrance policies that rely on testing rather than vaccines.

Data from Adara suggests travel interest was highest to the Dominican Republic before other Caribbean islands put vaccination mandates in place beginning earlier this summer. Most travelers to the Dominican Republic don’t need to present a negative test, but some are subject to Covid-19 breath tests upon arrival.

As vaccination rates increased among the island’s top markets — namely, the United States and Canada — travel interest dropped. Covid infection rates in the Dominican Republic decreased from June to August, but interest and searches did not rebound accordingly.

Research suggests that islands with lenient protocols — i.e., those without quarantines or vaccine mandates — are likely attracting unvaccinated travelers while deterring vaccinated ones. 

“Vaccinated people want to vacation in places that had stricter requirements, so they aren’t mixing with the unvaccinated,” said Adara’s chief marketing officer Carolyn Corda.

Puerto Rico’s tourism authority, Discover Puerto Rico, has said that the island has a vaccine mandate, though it does not have one.

Discover Puerto Rico’s website says that “vaccinations are required” for guests and employees in its hotels, house rentals, restaurants and bars. Discover Puerto Rico’s CEO separately confirmed the vaccine “mandate” to CNBC.

But a closer look at Puerto Rico’s restrictions shows that a negative Covid test on arrival, and weekly negative tests afterward, will suffice without a vaccine. Asked for clarification, a representative for Discover Puerto Rico told CNBC that “the ‘mandate’ refers to the need for either vaccination or frequent negative testing.”

Discover Puerto Rico’s CEO Brad Dean said vaccination rates among travelers to Puerto Rico rose from 9% in May to 58% in August.