Remdesivir, a drug thought to be one of the best prospects for treating Covid-19, failed to have any effect in the first full trial, it has been revealed.

The drug is in short supply globally because of the excitement it has generated. It is one of the drugs Donald Trump claimed was “promising”.

In a “gold standard” trial of 237 patients, some of whom received remdesivir while others did not, the drug did not work. The trial was also stopped early because of side-effects.

News of the failure was posted on a World Health Organization clinical trials database, but later removed. A WHO spokesman said it had been uploaded too soon by accident.

“A draft document was provided by the authors to WHO and inadvertently posted on the website and taken down as soon as the mistake was noticed. The manuscript is undergoing peer review and we are waiting for a final version before WHO comments,” said Tarik Jasarevic, a WHO spokesperson.