NEW YORK (NewsNation Now) — The discovery of two new strains of COVID-19 is meeting with quick action around the globe, although there’s some disagreement about the appropriate course.

Dozens of countries have banned travel from South Africa and the U.K., where the coronavirus variants were first reported, but U.S. health experts aren’t certain that’s an effective approach, saying mask-wearing and social-distancing likely remain more effective ways of controlling the virus.

The nation’s largest city is taking no chances, announcing dramatic measures Wednesday to limit the spread. Effective immediately, all travelers to New York from Britain will face a mandatory 14-day quarantine. The city’s mayor promised it will be carefully enforced, with consequences for noncompliance.

“Specifically, for folks coming in from the U.K., given that particular concern,” said Mayor Bill De Blasio. “We’re going to have sheriff’s deputies go to the home or the hotel of every single traveler coming in from the U.K. We are really serious about the fact that if you violate quarantine, you are creating a danger for everyone else.”

Travelers who defies the order could face a penalty of $1,000 per day.

The Trump administration says it’s monitoring developments with the new COVID-19 variants, and while there’s currently no current CDC recommendation for restrictions on travel, that may change as British officials work to contain the spread. While the new strains appear more infectious than the original, there’s no evidence so far that they’re more deadly. 

“Amid all of this difficulty, the great hope for 2021 is, of course, the vaccine,” said British Health Secretary Matt Hancock. “The vaccine is our route out of all this.”

As he was speaking to reporters in London, truck drivers were scuffling with police in the country’s southeast, stuck in a sort of no man’s land as they attempted to cross the English Channel en route to France, which had closed its border.

Neither of the new strains has been detected in the U.S., although officials suspect at least one is already here, telling NewsNation that the major drugmakers have already been evaluating whether their vaccines will still be effective. The short answer is yes.

In a statement, Pfizer points out that a virus mutating into new variants is completely normal.

“Since the emergence of the new coronavirus, SARS-CoV-2 in late 2019, experts have closely monitored and determined that there is more than one strain,” the company said. “To date, we have found consistent coverage of all the strains tested.”

Moderna Inc said on Wednesday it expects that the immunity induced by its COVID-19 vaccine would be protective against the coronavirus variants reported in the UK.

The company said it plans to run tests to confirm the vaccine’s activity against any strain.

Officials said Virgin Atlantic, British Airways and Delta Air Lines have all agreed to test passengers traveling to New York City from the United Kingdom for COVID-19.