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Pandemic: Disillusionment with the development of Covid-19 drugs

The third wave of coronavirus is rolling across Germany. While several vaccines were approved at record speed, doctors still lack effective drugs to treat their patients – despite research on drugs against corona, which is supported by billions of dollars around the world.



The number of people infected with the coronavirus is constantly increasing. This selection of articles gives an insight into the effects of the infection:

Around 400 different substances are currently being tested for effectiveness against Sars-CoV-2, says Stefan Kluge, coordinator of the treatment guidelines of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI). So far, however, there have been negative results in almost all studies.

Recently, “a bit of disillusionment” occurred in the development of drugs, says the infectiologist Clemens Wendtner from the Munich Clinic. Hopes still rest on synthetically produced antibodies that are supposed to put the virus out of action in the body. But expectations are now subdued. A number of so-called antiviral substances are also being investigated. So far, however, there is no agent that specifically fights the virus.

So far, the anti-inflammatory and long-known corticoid dexamethasone has mainly been used in hospital patients. It is supposed to slow down an excessive immune reaction, which often occurs with Covid-19, and is one of the drugs recommended according to national guidelines.

Other anti-inflammatory agents are also being studied. The active ingredient tocilizumab, which has previously been used against rheumatoid arthritis, could be approved in the foreseeable future. In addition, doctors use tried and tested drugs that, depending on the course, provide protection in the event of certain complications. Clinic patients often get blood thinners – because Covid-19 increases the risk of thrombosis, heart attacks and strokes.

Antibiotics are also often given because of the risk of additional bacterial infection. But these are ineffective against the virus and only make sense in certain cases, warns Kluge, who is also head of intensive care medicine at the Hamburg University Clinic in Eppendorf. Worldwide antibiotic consumption has risen rapidly with the pandemic – among other things, this will lead to further resistances. “Primarily, antibiotics have no place in Covid-19. You have to look very critically. ”

It is unlikely that an all-round effective cure for Covid-19 will be found at all. “We won’t find anything that reduces the current mortality rate from 20 to 30 percent in the intensive care unit to 0 percent,” says Kluge.

For flu and other viral diseases, there is still a lack of direct remedies. “There are only limited effective therapy options for other respiratory viruses,” says Christoph Spinner, senior physician for infectious diseases and pandemic officer at the Klinikum rechts der Isar at the Technical University of Munich (TUM).

“This is mainly due to the fact that there is only an early window for antiviral approaches in the case of respiratory diseases, while more immunological therapies are then required in the more complicated later phases of the disease.” Dexamathasone reduces mortality significantly, but not to zero. “That is why preventing the serious infection through vaccination simply makes the most sense.”

Synthetically produced antibodies are currently being tested in several clinics in Germany: Bamlanivimab and REGN-COV2, which ex-President Donald Trump also received. Despite poor studies and a lack of recommendations, the federal government had secured 200,000 doses of both drugs for around 400 million euros.

They are now in the closet, as doctors report. Only one of 100 therapeutic Bamlanivimab units had been used at the Munich Clinic by the beginning of March; there have been similar experiences in other clinics, says Wendtner. “This is not the blockbuster that is constantly being pulled out of the pharmacy cabinet.”

Doctors in Germany are only allowed to administer the agent to selected patients in the clinic in the early phase. If it is given too late, the body could already have produced its own antibodies, says Wendtner. “The drug can then trigger a severe immune reaction, including an allergic shock.”

In the USA, the authorities meanwhile say that bamlanivimab should no longer be used as the sole antibody because it does not help against many corona variants. On the other hand, experts from the RKI recently wrote, referring to laboratory experiments, that bamlanivimab was effective in variant B.1.1.7, which is now dominant in Germany.

So-called convalescent plasma – antibodies obtained from the blood of those who have recovered – is also being tested further in Germany. The mechanism of action is comparable to that of synthetic antibodies. Nationwide, university hospitals asked those who had recovered from corona for blood plasma donations a year ago. However, the statements on effectiveness are “heterogeneous”, says Spinner from the Klinikum rechts der Isar.

Research is also being carried out into drugs that prevent the lungs from being destroyed. It is about so-called mesenchymal stem cells. They are obtained from umbilical cord tissue, are precursors for various cell types in the body – and, according to initial studies, could help seriously ill corona patients. They are supposed to protect or regenerate lung tissue.

Months ago, the approval of Remdesivir, originally developed against the Ebola virus, was celebrated as a milestone. The drug is now rarely used, as doctors unanimously report. The malaria drug chloroquine proved to be ineffective and sometimes even contraindicated. Trump had praised this as a miracle weapon and “gift of God” at the beginning of the pandemic. The FDA granted the drug emergency approval – which was withdrawn after a few weeks.

Meanwhile, the anti-wormer drug ivermectin has also proven to be a flop. Especially in Latin America, people bought the shelves empty after reports of alleged success with Covid treatment – but a clinical study recently found no effectiveness in Corona.


(tiw)

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