A Liverpool professor has warned President Donald Trump's bizarre advice about taking an anti-malarial drug to protect against coronavirus could kill vulnerable people.

Calum Semple, Professor in Outbreak Medicine and Child Health at the University of Liverpool, spoke on national TV this morning and issued a strong rebuttal of Mr Trump's suggestions.

The 45th president of the United States said yesterday that he had been taking hydroxychloroquine, designed to target malaria, rheumatoid arthritis and lupus, for around a week and a half.

His decision appears to stem from anecdotal reports that the drug could have some effect against the virus, but there has as yet been no clear cut evidence to back that up.

And health officials are now scrambling to warn the public that hydroxychloroquine can have devastating side effects - especially to those most at risk of severe illness from coronavirus.

Calum Semple, Professor of Outbreak Medicine at the University of Liverpool, appearing on BBC Breakfast on Tuesday May 19

She said: "Our lead story this morning is about President Trump taking this anti-malaria drug hydrodroxycloroquine, in order, he says, to protect himself against coronavirus, we've had clear medical advice on this programme, it's not recommended?

Prof Semple, who is leading multi-million pound research programmes into the disease, replied: "Absolutely not. The people most at risk of severe COVID disease, and we know this from good studies so this is robust evidence, have greater amounts of kidney disease, liver disease and diabetes.

"And chloroquine is absolutely contra-indicated for people who have diabetes and are taking specific anti-diabetes drugs, it can cause a profound drop in the blood sugar, and that can lead to death, OK? So let's just be absolutely clear about this, this is not something that we're recommending particularly for those people most at risk of severe disease.

"It also causes problems for people with liver disease and the elderly, that have got poor kidney function, they're at high risk of side effects from chloroquine as well, so I'm sorry, I'm very disappointed to hear this."

Calum Semple, Professor of Outbreak Medicine at the University of Liverpool, who will be leading work on a new £1million lab to tackle coronavirus
Calum Semple, Professor of Outbreak Medicine at the University of Liverpool, who will be leading work on a new £1million lab to tackle coronavirus

President Trump told the media he "seemed to be OK" while taking the drug, and suggested "What do you have to lose?"

Mr Trump had previously caused outrage and confusion by appearing to suggest that disinfectant and sunlight could be trialled as coronavirus treatments - prompting cleaning product manufacturers to warn customers not to ingest their products.

On BBC Breakfast, fellow guest Professor Claire Hopkins, president of the British Rhinological Society, added: "Well I'm not taking hydrodroxycloroquine but equally I'm not spraying Dettol up my nose; I think we've already seen some of the impact of President Trump's advice, and my advice would be not to follow his medical advice."