A “very potent” experimental coronavirus drug being given to Donald Trump is already being used in a handful of UK hospitals, according to an Oxford University professor.

The US president was given the artificial antibody treatment at the White House on Friday after being diagnosed with Covid-19, before he was taken to Walter Reed National Military Medical Centre.

The drug began being used in “about three hospitals in the north” last weekend as part of Oxford University’s national Recovery trial, said Professor Peter Horby.

Prof Horby, who specialises in emerging infectious diseases at Oxford University and is co-chief investigator of the Recovery trial, added that the drug is due to be rolled out to “another 30 to 40 hospitals” in the UK next week.

Speaking on BBC Radio 4’s Today programme on Saturday morning, Prof Horby described the drug as “very promising” and “very potent”.

He said: “The class of drugs, these artificial antibodies, have been around for quite a while now, and they’ve been extensively used in inflammatory conditions and cancers, and they’re pretty safe and well understood, and so the technology is something that I think we have confidence in.

“This particular drug has probably been given to, I would think now, four or five hundred patients, mild or severe patients in different trials, and so far there’s been no worrying safety signals.

“In the laboratory, in cell cultures it has a very strong effect against the virus, and there have been studies in artificial animals where it also shows benefits. So probably of the drugs that are available, it’s one of the most promising.”

Prof Horby said a single dose of the treatment provides “prolonged protection” for “a month to six weeks”, making it “quite attractive for the older population”.

The antibody cocktail works by binding to a protein on the surface of the virus, stopping it from attaching to cells and replicating, while allowing the immune system to attack the virus.

Mr Trump has been given the drug alongside Remdesivir, an antiviral treatment which has been shown to help some coronavirus patients recover faster.

His wife Melania and one of Mr Trump’s closest aides also tested positive for Covid-19 on Friday.