The US has bought up almost the entire global supply of one of two drugs used to treat coronavirus.
Remdesivir, which was developed to treat Ebola, is produced almost exclusively by US pharmaceutical giant Gilead Sciences – and it has been priced at $2,340 (£1,892) per patient in wealthier nations.
The company has agreed to send nearly all of its supply of the drug to the US over the next three months.
This means remdesivir will not be available for use on patients in the UK and Europe until October, Dr Andrew Hill, a senior visiting research fellow at Liverpool University, told Sky News.
He said: “This deal that’s been struck by America means that people with COVID-19 in the UK can’t get access to these treatments that would get them out of hospital quickly and might improve their chances of survival.
“So far, we know that for the next three months there will be no supplies of remdesivir – America will take the drugs and we won’t have access to them. That’s the case in the UK and Europe.”
Low and middle-income countries can produce generic versions of the drug, but are unable to sell them to Europe because Gilead has a patent for it, he added.
It comes after health officials warned the number of new US cases reported each day could hit 100,000 after a spike in infections.
Trials of the antiviral medicine on coronavirus patients have showed it reduces the length of time they experience symptoms from 15 to 11 days by stopping the virus reproducing.
Health Secretary Matt Hancock described the use of remdesivir on COVID patients as the “biggest step forward in the treatment of coronavirus since the crisis began”.
NHS bosses had hoped to roll it out to adults and teenagers suffering severe symptoms in UK hospitals, but the US move appears to have put this on hold.
Another drug that appears to lessen symptoms in coronavirus patients is a common steroid called dexamethasone.
But unlike remdesivir, it is cheap to produce and widely available across the globe.