Breakthrough in treatment of Covid-19

Surprises are never far behind in medicine. Still, this is a major advance while awaiting more specific antiviral therapy

By Dr R Neerunjun Gopee

Ever since the declaration of the Covid-19 pandemic by WHO at the beginning of March, and its unrelenting spread across the world, the only comforting piece of news that came our way after several weeks was that at least a few countries had been able to contain it by rigorous application of measures recommended.

So-called ‘controversies’ are reported (about the use of hydroxychloroquine for example) – but these must be viewed as the serious and sincere attempts being made to find effective solutions. Photo – hindustantimes.com

These, as is well known by now, included contact tracing and scaling up testing, and the sanitary precautions like physical distancing, wearing of face mask, frequent hand washing/use of sanitisers among others. Thus Vietnam, Taiwan, South Korea and Singapore stood out as examples of such successful containment, although the latter two countries have had to face a second wave subsequently. New Zealand declared itself Covid-19 free last week – but a few days ago has reported two cases imported from the UK.

Now we can include Mauritius too, as we have been able to date not only to limit the spread but to remain free of any new case for nearly a month, and that allowed us to gradually lift the lockdown.

Two days ago came a piece of breaking news from a team of scientists at Oxford University, UK which could prove to be a game changer in the treatment of the disease. In a clinical trial involving 2100 patients, they have found that the drug dexamethasone has a significant effect on the mortality rate of patients who are severely affected.

In fact, the strategy of control of Covid-19 is the same as that for any infectious disease: prevention, treatment, vaccination. Prevention is a very effective tool, and yet is the most difficult to apply because it means compliance with public health measures by the people, who are often reluctant to abide by the rigorous measures needed. That is why, guided by the scientific and medical evidence available, authorities have to combine a mix of soft incentivizing and harder legal provisions to deal with the problem, especially when the disease assumes epidemic or pandemic proportions.

Vaccination and treatment present a different order of challenges and difficulties, more so when the disease is a new one. To start with, after identifying the infective agent – in this case a virus – it has to be ‘characterised’, that is, its structure and properties have to be studied in great detail and its mode of transmission worked out.

Further, the symptoms it produces have to be observed and catalogued, followed by deeper study of the disease patterns that are evolving and the organs affected, and the ‘how’ and ‘why’ of the underlying processes understood in detail. This will involve carrying out post-mortems as well, to get a clearer picture of the changes that take place in the organs concerned.

By putting all this information together, scientists and doctors are able to by the by obtain a more coherent picture of the disease and the possible treatment options that may be available, based on experience with previous medications as well as being able to think of possible new ones according to the findings gathered.

It will be appreciated that all this cannot happen overnight, and that is why we have to have many teams around the world focusing on different aspects of the disease and adopting a variety of approaches, and then sharing experiences by direct contacts or through publications. As new observations and findings emerge, decisions about prevention and treatment inevitably undergo modifications that reflect the dynamically evolving situation. That is why at times so-called ‘controversies’ are reported (about the use of hydroxychloroquine for example) – but these must be viewed as the serious and sincere attempts being made to find effective solutions as rapidly as possible.

Because vaccine development is both uncertain – at least initially – and takes a longer time, in particular because of concerns about efficacy and safety, that is why much hope is pinned on what is more familiar to the doctors busy treating the disease (clinicians) rather than preventing it (public health specialists). At the beginning, an attempt is made to treat the symptoms, and this is usually possible with familiar medicines.

The problem is that there are very few specific treatments for viruses, unlike in the case of bacteria for which a large range of antibiotics are known. Whether or not an anti-Covid-19 antibiotic will be found cannot be guaranteed, and we therefore have to resort to existing drugs, and repurpose them as it were to deal with particular aspects of the disease where we have reason to presume that they may have a beneficial effect.

In the case of the pneumonia caused by Covid-19, a phenomenon known as ‘cytokine storm’ became evident as studies got underway. It is an excessive response of the patient’s immune or defence system to the virus, which results in the release of a number of substances which as well as fighting against the virus actually cause much damage to the lungs, what is referred to as an ‘overdrive’ of the immune system. This is part of the overall inflammatory response to the presence of the virus.

One category of drugs which have powerful anti-inflammatory effects is steroids, and dexamethasone is one such medication that is widely used and well-known in terms of its effects and side-effects. In the Oxford study, it has reduced the death rate for patients on ventilators by a third, and by a fifth for those on oxygen therapy. However, it has no benefit for patients who are not so severe as to require oxygen or ventilators. The medical authorities in the UK are recommending its use on the basis of these promising results, moreover because the drug is both readily available and relatively cheap.

It goes without saying that caution will still be needed as dexamethasone is rolled out for treatment of the virus, because surprises are never far behind in medicine. Still, this is a major advance while awaiting more specific antiviral therapy, and a most welcome development in the management of disease that will definitely save a lot of lives.

Another first was recorded last week, when in Chicago lung transplant surgeon Dr Ankit Bharat carried out the procedure in 20-plus young woman who had no hope of recovery otherwise – an operation that lasted nearly 10 hours because it took much time to separate the lungs from the other tissues to which they were stuck  by the inflammatory reaction. This is obviously an operation that will not be available to everybody, and the treatment with dexamethasone will hopefully prevent the progression of disease so as to obviate the need for such extreme surgeries of last resort.

* Published in print edition on 19 June 2020