Of all the negative storylines about immigrants in U.S. history, few resonate stronger than the one that portrays them as carriers of dangerous illness.

Tuberculosis. Diphtheria. Measles. Trachoma. Influenza. The latter, especially, remains relevant today.

Depending on the era and the whims of public opinion at the time, the screening processes used often reflected less medical concern than bias about who was suitable to become a new American. Such bias led to demoralizing disinfections and checks for lice among Asian and Mexican immigrants, with buttonhooks used to pry open eyelids and chalk marks to note whether arrivals at Ellis Island had passed or failed.

It’s a long, often scandalous history.

One would have hoped that by now our government would be able to ensure that every possible health scare — real ones, not imagined — were appropriately addressed. But we can’t make that claim.

The U.S. government, through Customs and Border Protection, is refusing to acknowledge the reality that they’ve helped to create. There is a need to vaccinate against the flu inside the detention shelters at the U.S.-Mexico border where scores of Central American migrants are being held.

It’s horrendous enough that we’ve chosen to warehouse desperate humans like chattel. And it is a choice. The numbers of Central Americans requesting asylum are more than the system was set up to manage, especially the children. But at nearly every turn, the Trump administration has chosen routes to deny hope and fairness.

It even dismissed the recommendation of the Centers for Disease Control and Prevention, which asked that the migrants be vaccinated against the flu at the soonest possible juncture. Medical experts have urged the vaccinations be given.

Concern has even been raised by the guards of these facilities, as the flu is extremely contagious, able to spread by coughing, sneezing and contact with surfaces. And it’s deadly. In the 2017-18 flu season, a staggering 80,000 people died of the flu in the U.S.

Three migrants have died of the flu while in U.S. custody this year. There’s video of one death, nearly unbearable to watch.

Carlos Gregorio Hernandez Vasquez, a 16-year-old from Guatemala, can be seen stumbling and falling in his cell in a Texas border station. He was found dead later by another young inmate. The video was obtained through an investigation by ProPublica.

Carlos had been diagnosed with the flu and had shown a temperature of 103. He died in May.

Yet it took doctors being arrested in mid-December outside of a San Diego area detention center before officials would even take the matter of swift flu vaccinations under advisement. The doctors showed up, with about 100 vaccinations, offering their services.

A Homeland Security spokesperson tweeted this in response: “Of course Border Patrol isn’t going to let a random group of radical political activists show up and start injecting people with drugs.”

Yes, vaccinations would have to be managed under secure protocols. But the smart aleck refrain is telling for its dismissiveness.

Policy dictates that children who arrive at the border without a parent or guardian won’t be held longer than 72 hours before they might be processed into centers that are equipped to offer vaccinations.

But many migrant children are often being held longer. Sometimes children are held for up to a week, due the crush of the numbers arriving and haltingly slow way they’re requests for asylum are being processed.

The struggle to provide flu vaccinations to the migrants at the border is but one issue complicating the lives Central American immigrants.

But, heartbreakingly, it illustrates the lack of mercy and common sense that blots our nation’s immigration history.