Taking hydroxychloroquine shortly after being exposed to COVID-19 does not help prevent infection in a statistically meaningful way, scientists reported Wednesday following a clinical trial. This trial significantly casts doubts on the effectiveness of the much touted cure for Covid-19, and now the arena is wide open for researchers to come up with a vaccine for the disease that has ravaged the planet.
The medicine has been touted by US President Donald Trump, who has said he used it as a prophylaxis against the novel coronavirus.
But an experiment involving 821 people across the United States and Canada showed it did not work significantly better than a placebo for this purpose.
The study was led by a team at the University of Minnesota, and their paper was published in the New England Journal of Medicine.
Hydroxychloroquine not the cure for Covid-19 as it was once claimed
Researchers enrolled adults who had come into contact with someone who had a confirmed case of COVID-19 for more than 10 minutes at a distance of six feet (about two meters) or less.
The majority of them — 719 — were deemed to have had “high-risk” exposure because they wore neither a face mask nor an eye shield at the time, while the rest were “moderate-risk” because they covered their face but did not have goggles.
All participants were randomly assigned to receive either hydroxychloroquine — which is certified for use against malaria, rheumatoid arthritis and lupus — or a placebo, within four days.
The researchers then looked at how many patients went on to develop COVID-19 over the next two weeks, which was confirmed either by a laboratory test or by clinical signs. They found that 49 of the 414 given the medicine got the disease caused by the coronavirus, compared to 58 of the 407 on the placebo.
A randomized clinical trial shows that hydroxychloroquine was no more effective than a placebo in preventing healthy people exposed to COVID-19 from getting the disease.https://t.co/j5cQyHXfEe
— Justin Baragona (@justinbaragona) June 3, 2020
This translates to 11.83 percent on the drug were infected, versus 14.25 percent on the placebo. The absolute difference of about 2.4 percentage points in favor of the medicine was not considered statistically significant given the sample size, meaning it could have occurred because of chance.
Side effects were more common with hydroxychloroquine than with the placebo — 40.1 percent versus 16.8 percent — but no serious adverse reactions were reported.
“This randomized trial did not demonstrate a significant benefit of hydroxychloroquine as postexposure prophylaxis for COVID-19,” wrote the authors.
The results of the study were eagerly awaited because it was a randomized controlled trial (RCT), a carefully designed experiment that is considered the gold standard for investigating clinical outcomes.
Earlier studies also cast doubt on drug’s healing ability
Several previous studies on the drug that have made headlines were “observational,” meaning they looked back at what had already happened. As such, more variables are left to chance and it is generally harder to draw firm conclusions.
Nevertheless, Martin Landray, a professor of medicine and epidemiology at the University of Oxford, said more research was needed to know for sure whether hydroxychloroquine might have a moderately positive effect.
“The study is too small to be definitive,” said Landray, who was not involved in the trial.
The results “makes it very unlikely that there is a large effect (e.g. a halving in the risk of infection) but cannot rule out a more modest difference (e.g. a reduction of one-quarter or one-third) which would still be very valuable,” he added.
Cure for COVID-19: Background of Hydroxychloroquine
President Donald Trump on Monday made the surprising revelation that he is taking hydroxychloroquine, an anti-malaria drug that his own government experts say is not suitable for fighting the novel coronavirus.
Trump, noting that he has tested negative for the virus and shows no symptoms, said he’d been taking the drug as a preventative measure “for about a week and a half.” However, it is not clear whether he started this measure as a response to the recent developments of several White House members succumbing to the coronavirus.
“I take a pill every day,” he said, adding that he combines this with zinc.
Asked why, he said: “Because I think it’s good. I’ve heard a lot of good stories.”
Trump has shown interest for weeks in promoting the use of hydroxychloroquine, even if some doctors think it does not work for coronavirus patients and US government regulators warn it has “not been shown to be safe.”
President Trump said, “I’m taking it, hydroxychloroquine, right now, yeah. A couple of weeks ago, I started taking it.”
BBC further adds that when asked what was his evidence of hydroxychloroquine’s positive benefits, Mr Trump said: “Here’s my evidence: I get a lot of positive calls about it.”
AFP with additional input by GVS News Desk