Battling long Covid with drugs
By 
Clare Sansom2023-10-24T09:51:00
The challenge of finding drugs for a poorly understood disease with many symptoms is clear. Clare Sansom looks at the work going on to help the people suffering in its shadow
The WHO’s formal diagnostic definition of long Covid is ‘… the continuation or development of new symptoms 3 months after the initial Sars-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation’. That encompasses, almost literally, a multitude of problems. Whereas there are a handful of very common ‘classic’ symptoms - fatigue, breathlessness, loss of smell, muscle pain and the neurological condition usually described as ‘brain fog’ – the complete list includes about 200 possible ones. Long Covid can occur after an original infection that was trivial or even symptomless, but anecdotally at least it is more severe and longer lasting when the original infection was itself severe.
There are an estimated 65 million people worldwide with long Covid. Most patients do seem to improve over time, but their recovery is painfully slow. A recent study found very few complete recoveries in a population of over 300 long Covid patients over two years.
In such a complex condition, it is particularly difficult to drill down to the molecular level find the links between the original infection and subsequent pathology, and thus the root cause of the disease. This is important if we are to discover drugs that will modify the course of the disease rather than just treating its symptoms.