London - Scientists the world over are working round the clock to find a cure for the deadly coronavirus.
With little time to develop new medicines from scratch - and a vaccine to prevent the infection thought to be at least a year away - much of their effort involves "repurposing" existing treatments.
This means testing drugs currently used to treat other conditions to see if they can halt, or even slow, the spread of Covid-19. As soon as a drug is linked with helping corona patients, it sells out as countries scramble to get their hands on it.
"I am more optimistic about these existing drugs being put into use in the near future than I am about a vaccine," says Professor John Oxford, a virologist at Queen Mary University of London. "We have extensive experience with many of them already and some could be easily repurposed."
So what are these treatment candidates - and could they really help?
ANTI-MALARIAL
Chloroquine and hydroxychloroquine tablets cost less than £1 (about R23) a day and have been used against malaria for about 70 years. Recent studies have also found they can act against some viruses.
Scientists think the drugs may work by changing the chemical structure of cells in the lungs just enough to stop the Covid-19 virus binding to them and causing widespread infection. But chloroquine can cause cardiomyopathy, a type of heart failure.
Trials are under way in the US and China to see if they can speed recovery in those with Covid-19. Professor Robin May, a specialist in infectious diseases at Birmingham University, says: "The drugs are cheap and could be fairly easy to accelerate into trials and, if successful, to treatment."
Initial results from trials in China suggest they may help to slow down the rate at which the Covid-19 virus replicates.
EBOLA DRUG
Remdesivir is an antiviral drug that is injected into the bloodstream and was originally developed to tackle Ebola. It interferes with the virus’s genetic make-up so it can’t reproduce rapidly and infiltrate the lungs, causing pneumonia. But remdesivir can trigger nausea, vomiting and, in severe cases, liver damage.
Trials are under way in China and the UK after some Covid-19 patients responded well to treatment. British patients are being given the drug to see if it stops the virus rampaging through the body. Initial results are expected in the next month or so.
ARTHRITIS JAB
Kevzara (also called sarilumab) is given as an injection into the bloodstream to treat painful, swollen joints in rheumatoid arthritis.
It works by slowing the release of IL-6, a chemical messenger produced by the immune system which is linked to inflammation.
Trials in the US and Europe will now see if injections of sarilumab can reduce inflammatory processes in the body set off by Covid-19 that lead to pneumonia. In tests of a similar drug in China, 19 out of 20 seriously ill patients with Covid-19 were discharged from hospital within two weeks.
ASTHMA INHALER
A drug that was being developed in the UK for asthma is being fast-tracked into trials for Covid-19. Called SNG001, it was given rapid approval in March by the Medicines and Healthcare products Regulatory Agency (MHRA) after the World Health Organisation said it might be useful in fighting the virus.
A trial of 100 Covid-19 patients is getting under way at University Hospital Southampton.
Delivered by inhaler, the drug raises levels of interferon beta-1, a protein that dictates the immune system’s response to viruses that affect the lungs. Covid-19 suppresses production of this protein, which allows the virus to evade detection by the immune system.
‘DRACULA’ CURE
Scientists are exploring whether injecting sick patients with a treatment made using the blood of people who have survived Covid-19 could stop the virus in its tracks.
The treatment, which has so far been used on about a dozen Covid patients in the US, uses plasma - a liquid component of blood - taken from survivors, which contains antibodies (proteins released to combat an infection) against Covid-19. It is then slowly fed into another patient’s bloodstream.
The theory is that extracting antibodies from survivors’ blood and injecting them into patients could halt Covid-19. But the numbers involved are currently too small to show if it works well.
MS TABLET
A pill taken by thousands of patients in the UK with multiple sclerosis (MS) is also being investigated as a potential weapon against Covid-19. Fingolimod works against MS by helping to dampen down inflammation in the central nervous system that causes severe mobility problems.
There is some evidence to suggest it may help prevent acute respiratory distress syndrome (ARDS), a common complication of Covid-19 infection that leaves patients gasping for breath and in need of a ventilator.
In a trial that began in China in February, sick patients are being given a 0.5mg fingolimod tablet every day for three days to see if it speeds recovery. The results are expected in July.
UNLIKELY CHOICE?
No drug is more synonymous with devastating side-effects than thalidomide, the pill given to thousands of pregnant women in the UK in the Fifties and Sixties to combat morning sickness.
It left a generation of children with deformities — but it could now help to combat Covid-19. Two trials, involving 140 patients, are under way in China after doctors there reported the case of a 45-year-old woman who recovered after being given 100mg of the drug daily, alongside a range of other treatments, for five days.
Thalidomide is thought to have anti-inflammatory effects that may control the ‘storm’ inside the lungs that some Covid-19 patients endure. Scientists hope it will reduce lung damage and shorten the duration of illness.
'SUNSHINE' PILL
This week, scientists from the University of Granada in Spain are set to begin a ten-week trial to see if vitamin D can help to fight the virus. They will be testing the vitamin on 200 Covid-19 patients with mild to moderate symptoms. Each will be given a pill every morning to take with a slice of toast and olive oil - to improve absorption through the gut.
Vitamin D, which we mostly get from exposure to the sun’s rays, plays a crucial part in maintaining a healthy immune system, so this may improve people’s chances of withstanding the onslaught of a severe infection such as Covid-19.
HEAD LICE REMEDY
Researchers in Australia revealed last week that ivermectin, an anti-parasitic drug used to treat head lice and scabies, could stop Covid-19. Tests at the University of Melbourne showed it reduced levels of the virus in infected cells by almost 100 percent within 48 hours by "paralysing" it, attacking its nervous system and interrupting its reproduction process. But the head lice remedy has yet to be tested in clinical trials on humans.
Daily Mail
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