Covid-19: in the midst of the vaccine breakthrough, where is the search for cures?

Entering another dimension following the announcement by four manufacturers of a convincing efficacy rate, the global race for Covid-19 vaccines has focused all attention since November 9. To the point perhaps that we forget that scientists all over the world continue to search intensely for cures against this new disease that appeared a year ago. While no miracle cure has been discovered for the time being, some drugs have still been tried for certain categories of patients or to avoid certain complications. Others, on which there was however much hope, were permanently removed from the list, failing to demonstrate their benefits, in particular to reduce mortality.

Since the end of September, the Institut Pasteur de Lille has maintained a certain mystery around a “miraculous” molecule against Covid-19, particularly in the initial phase of the disease. While his name is to remain a secret for the time being, and this in particular to preserve supplies, some details have nevertheless been given on what appears to be fundamental advancement.

“We have shown in vitro (in the laboratory) that a molecule present in the active ingredient of an existing drug is active against the coronavirus. We tested it on human lung cells and the results were very promising“, explained Prof. Benoît Déprez, scientific director of the Institut Pasteur de Lille (IPL), in The voice of the North. “Taken at the first symptoms of the disease, this drug reduces the viral load of the carrier of the disease, prevents contagion. Taken later, it counteracts its severe forms. Its action is that of an antiviral and not that of an anti-inflammatory“, he further specified to our colleagues. And in detail:”We have shown that its active ingredient can kill the virus at a concentration thirty times lower than that substantially proposed (…) We hope to be able to start these tests by the end of 2020.“Results are expected in late spring 2021.

At the same time, the Institut Pasteur de Lille is working to find a treatment against all coronaviruses, which would prevent mutations or future epidemics. “It is a project that we are developing at high speed, with the discovery of a dozen interesting molecule families.“, indicates Benoît Déprez.

Since September, the World Health Organization and the European Medicines Agency have recommended the administration of dexamethasone based on the results of the large British study, Recovery. To date, this is the only treatment that has reduced mortality from Covid-19, although this only applies to one category of patients, namely severe cases requiring oxygenation. By reducing the out-of-control immune system responsible for the inflammation characteristic of severe forms, this corticosteroid reduces mortality by 21% after 28 days. But since it lowers the immune system, it shouldn’t be given early in the disease.

In addition to dexamethasone alone, a work published September 2 in the American medical journal Jama showed that drugs from the same family, corticosteroids, would have the same effects on reducing mortality in patients suffering from Severe Covid-19. Since then, WHO has recommended “systematic use of corticosteroids in patients with severe or critical illness“.

Like corticosteroids, anticoagulants are used in the most severely affected patients, with the aim of preventing the formation of blood clots, one of the serious complications of Covid-19.

Among the treatments tested by the Recovery study, there is also tocilizumab, used in the treatment of rheumatoid arthritis. Researchers from Imperial College London announced on November 19 that tocilizumab appears to have a beneficial effect in fighting the inflammatory phenomenon responsible for the most severe cases. But these results are only preliminary and the data have not been published in a scientific journal.

It turns out that three studies were published at the end of October in the American journal Jama Internal Medicine has produced mixed results. The Recovery trial, which tests tocilizumab on a large scale, should shed some light on its effectiveness in the coming weeks.

In November, a new type of treatment received “aauthorization for emergency use“from the United States Medicines Agency (FDA). It is the treatment produced by the American biotechnology company Regeneron and another of the same type, produced by the pharmaceutical group Eli Lilly, which are based on the so-called” Monoclonal “antibodies manufactured in the laboratory. Injected via the route. intravenous, should support the immune system to neutralize the coronavirus. Donald Trump himself received this experimental treatment. Their efficacy, however, remains under evaluation, always as part of the ‘Recovery test.

What about transfusing patients with plasma (the liquid part of the blood) taken from people previously infected but now cured, so that they can benefit from their antibodies? According to some studies, this treatment has been shown to be effective in treating the Ebola virus or SARS, which belongs to the same family as the coronavirus responsible for Covid-19. But all experts agree that more clinical trials are needed to compare plasma to standard care. Again, the Recovery test studying this comparison should allow you to see more clearly.

The hope for remdesivir was short lived. This antiviral was the first drug to receive conditional marketing authorization on 3 July. Initially intended to treat Ebola hemorrhagic fever, it does not reduce mortality, concluded the large global clinical study Solidarity launched by WHO.

Same sentence for the hydroxychloroquine that has made most of the ink flow since the start of the pandemic. Used depending on the country as a treatment for malaria or autoimmune diseases and defended by controversial Professor Didier Raoult and US President Donald Trump, it has not provided evidence of its effectiveness against Covid-19 according to several studies, including the trial of UK recovery.

Finally, the lopinavir-ritonavir combination, marketed under the name Kaletra, does not reduce mortality or the risk of undergoing artificial ventilation, according to the results of Recovery. Even this treatment does not reduce the length of hospitalization.