Covid-19 is undergoing a clinical trial in humans that could cause complications and prove fatal
A new Covid-19 variant could show immune evasion and enhanced transmissibility, South African scientists warn
A new drug used by a woman to combat her chronic blood disorder could cause complications and prove fatal, South African scientists have warned.
Covid-19 (the 26th version of C difficile) is undergoing a clinical trial in humans at a hospital in Africa where the infection kills an estimated 30,000 people a year.
The drug, currently licensed in the US for treating malaria, works to fight blood-borne infections by inhibiting the activity of immune cells that can invade the cells that fight infection.
It is administered intravenously in combination with vancomycin and is thought to have dramatically reduced fatalities from the bacterial infection among patients in clinical trials.
But some scientists have raised concerns about potential side-effects, including increased possibility of drug-resistant strains developing and complications, such as kidney failure and fractures.
New strains developed on the drug may trigger the bowel to multiply through “immune evasion”, according to the researchers, who led a paper published in the journal PLOS Medicine this week.
“We were always quite worried that infections, or pro-drugs [candidate therapies] would be resistant to this treatment,” said Prof Conundrum Limbroeke, who took part in the South African study.
“We were also worried that the adverse events might become more widespread because people would be living with resistant infection for years and not know it or would not recognise the damage they’ve done to themselves.”
According to the journal, Covid-19 might also prove transmissible, meaning doctors could treat patients with it without completely cutting them off from their immune system.
The researchers, however, have not yet established which variant of the drug is causing the side-effects, or whether the activity they are seeing is due to existing strains or a completely new strain.
“When they [people infected with the new strain] bleed from an artery or a fistula, blood flows from one end of the body to the other and can invade the cells that fight infection,” Limbroeke said.
The patients receiving Covid-19 were also exposed to higher concentrations of vancomycin, the standard drug for the treatment, than control patients.
The drug is only licensed for use in Africa, and Limbroeke described the South African study as a “proof of concept”.
“If the results in humans show that it’s been effective for that kind of infection, then it will be very important,” he said.
The drugs are available in pharmacies across South Africa for around $180 (£147) per month. The current trials in humans are being carried out by the South African Health Research Institute at Malvern University Hospital in Malvern, the western Cape province.
An expert on the drug, Prof Olle Foelle of the University of Malvern, said the trial was a “positive breakthrough” and urged authorities to increase the study.
“Despite Covid-19’s many potential benefits, there is a legitimate concern that this treatment has the potential to cause serious adverse effects and also to be transmissible, both of which should be taken seriously,” he said.
“The expertise and experience of the South African team was essential to permit the clinical trial to move forward, and I very much hope that these therapies will reach the continent and indeed the rest of the world as early as possible.”
A London-based spokeswoman for pharmaceutical giant Pfizer, the US manufacturer of Covid-19, said: “Our current C diff franchise is launched in Africa.
“This includes Covid-23 and would include Covid-24 if a replacement for Covid-19 is found through clinical trial. Covid-24 has not yet been submitted for regulatory approval but we believe it will be successful.”