A leading US public health official warned on Tuesday that a new wave of coronavirus hitting the US next winter could be “even more difficult” for America to deal with than the current outbreak.

And in a double blow for the prospect of ending the coronavirus pandemic, a US trial of the controversial treatment Donald Trump has referred to as “like a miracle” has produced poor results.

The Guardian reports Robert Redfield, director of the Centers for Disease Control and Prevention (CDC) federal agency, warned that a wave of coronavirus next winter would coincide with the normal influenza season.

“We’re going to have the flu epidemic and the coronavirus epidemic at the same time,” he said.

Having two simultaneous respiratory outbreaks would put unimaginable strain on the healthcare system, he told the Post.

He was also asked about increasing protests in a number of US states against stay-at-home orders from governors, with demonstrations coordinated on social media and evidence of backing by rightwing figures and powerful Trump allies. And about calls for states to be “liberated” from restrictions, which Donald Trump has himself echoed.

Redfield said in the interview: “It’s not helpful.”

“The nationwide study was not a rigorous experiment. But with 368 patients, it is the largest study yet of hydroxychloroquine, with or without the antibiotic azithromycin, for Covid-19.

Coronavirus has killed more than 44,000 people in the US so far.

“The study was posted on a website for researchers and has not been reviewed by other scientists. Grants from the National Institutes of Health and the University of Virginia paid for the work.

“Researchers analyzed medical records of 368 male veterans hospitalized with confirmed coronavirus infection at Veterans Health Administration medical centers who died or were discharged by April 11.

“About 28 percent who were given hydroxychloroquine plus usual care died, versus 11 percent of those getting routine care alone. About 22 percent of those getting the drug plus azithromycin died too, but the difference between that group and usual care was not considered large enough to rule out other factors that could have affected survival.

“Hydroxychloroquine made no difference in the need for a breathing machine, either,” the report said.

“Trump has repeatedly hyped the drug and the Food and Drug Administration (FDA) has provided hydroxychloroquine with an “emergency use authorization” to use on coronavirus patients in some circumstances. But the FDA has not conducted clinical trials to ascertain fully whether the drug is an effective treatment for Covid-19.

  •  Robert Redfield, the CDC director, warned that a wave of coronavirus in the winter would coincide with the flu season. Photograph: Rex/Shutterstock