Hopes of a cure for coronavirus are being pinned on chloroquine – a 70-year-old treatment for malaria – after doctors in France reported positive results. Does the malaria pill chloroquine work against coronavirus? Doctors in Marseille in the south of France have claimed that patients have successfully been treated with the malaria drug chloroquine. In a study of 36 patients 20 were given the drug. After six days, 70 per cent of the chloroquine patients were considered cured, that is the virus was no longer detected in blood samples, compared to just 12.5 per cent of the control group of patients. How much faith can we put in these results? This is a significant effect, says Dr Andrew Preston, reader in microbial pathogenesis at the University of Bath, who was not involved in the study. However, the study was conducted on a very small number of patients and would need to be replicated on a much larger scale to be scientifically convincing. Has it been used anywhere else? Doctors in Australia and China have also seen promising results with the drug and hope to start a trial within the next few weeks.

How might the drug work against coronavirus? Robin May, professor of infectious disease at the University of Birmingham, says that the process is not yet well understood. However, he speculates that a process called “endocytosis” - where the virus enters the host - may have something to do with it. “This means that the virus is initially taken up into an intracellular ‘compartment’ which is typically fairly acidic. Chloroquine would alter the acidity of this compartment, which can interfere with the ability of viruses to escape into the host cell and start replicating,” he says. “Another possibility is that chloroquine may alter the ability of the virus to bind to the outside of a host cell in the first place - which is an essential first step for entry.”