An analyst, who has penned viral posts, says strict border controls are the most effective tool for nations in slowing the spread of the Chinese coronavirus.

Analyst Tomás Pueyo, an executive at Course Hero, writes in the New York Times that it is border controls, above all other public health regulations, that are vital to slowing coronavirus:

Measures like masks, testing, contact tracing, isolations, quarantines are still necessary, but one approach has not been emphasized enough: the fence. Countries that quickly closed their borders or carefully monitored anyone coming in have been most successful in slowing infections. [Emphasis added]

Some countries use fences to block outsiders from crossing their borders. Some countries limit travel within their borders. As the United States considers relaxing some border controls and European countries reimpose travel restrictions, they need to realize that these fences are necessary to control the virus — and if they are enforced, they’ll be effective. [Emphasis added]

Pueyo writes that travel bans are the “most aggressive” forms of slowing the spread, citing their effectiveness when properly enforced. Quarantines, Pueyo argues, are the least effective, while checkpoints can be effective, as they individually assess arrivals.

In January, Trump implemented a travel ban on China which was quickly followed by travel bans on Iran, Europe, and eventually Brazil. Trump has also shut down nonessential travel at the northern and southern borders, as well as halted a number of visa programs to reduce foreign competition against unemployed Americans.

Democrats criticized Trump’s border controls, including Democrat presidential candidate Joe Biden. In January, Biden called Trump’s ban on travel to the U.S. from China “hysterical xenophobia.” In his original plan to slow the coronavirus, Biden makes no mention of banning travel from international hot spots.

Pueyo argues the travel bans should remain in place to control the coronavirus and could even be expanded upon with stricter guidelines to prevent thousands from arriving in the U.S. through loopholes.

While Democrats criticized Trump’s border controls, Americans have overwhelmingly supported the actions. In March, about 95 percent of Americans called travel bans the “most necessary” move to slow the spread of the coronavirus.

John Binder is a reporter for Breitbart News. Follow him on Twitter at @JxhnBinder.