Coronavirus: Oxford study says hydroxychloroquine can not be 'ruled out' as preventative measure, study says

Hydroxychloroquine should not be "ruled out" as prevention for coronavirus, according to researchers studying its effectiveness.

US President Donald Trump has repeatedly suggested the antimalarial drug can fight COVID-19 despite mounting scientific evidence that it can not and may be harmful.

The nation's top infectious disease expert Dr Anthony Fauci highlighted clinical studies concluding the drug is not effective in treating COVID-19 - including ones commissioned by the World Health Organisation and the US National Institutes of Health (NIH).

While acknowledging the drug has been ruled out as a treatment, a University of Oxford-led study is examining its effectiveness for prevention.

The Mahidol Oxford Tropical Medicine Research Unit (MORU) has enrolled 40,000 frontline workers in Europe, Africa, Asia and South America who will receive either chloroquine, hydroxychloroquine or a placebo.

It's hoped the double-blind, randomised study will reveal if hydroxychloroquine can prevent the virus from developing or greatly reduce chances of hospitalisation if taken soonafter infection.

One of the lead researchers of the 'Copcov' trial, Dr Will Schilling, said the question on whether hydroxychloroquine "works or not in prevention or very early treatment… remains unanswered".

"The benefits found in small post-exposure treatment trials, although modest, could be very valuable if they were confirmed."

Professor Nick Day from the Mahidol Oxford Tropical Medicine Research Unit, also guiding the study, was confident the study "will find out if these drugs can prevent COVID-19 or not."

"Prevention is much easier than cure," he said.

"By the time patients are admitted to hospital, virus multiplication is well past its peak and inflammation in the lungs and other complications may prove lethal."

"At this stage, the steroid dexamethasone, which reduces inflammation, saves lives but the antivirals hydroxychloroquine and chloroquine do not. However, that does not rule out that they could be effective much earlier in the illness."

There have been no results yet from the Oxford-led research or many ongoing studies around the world on the drug as a preventative treatment.

:: Listen to the Daily podcast on Apple Podcasts, Google Podcasts, Spotify, Spreaker

The Oxford-led study was recently paused following controversy over a study from The Lancet, which claimed the drug caused higher death rates and heart problems.

The WHO halted its research due to these fundings but resumed it after errors were found in the Lancet study.

President Trump has routinely defended the use of hydroxychloroquine as a treatment for COVID-19, recently saying unproven medication was only rejected as treatment because it was "politically toxic" as he had recommended its use.

In May, he revealed he was taking the medication daily to ward off coronavirus after consulting the White House doctor.

Brazilian President Jair Bolsonaro has also praised the drug and credited it for his recovery from coronavirus.