Trump fights covid thanks to mouse antibody

Donald Trump visits the Walter Reed Military Hospital in July this year.CHRIS KLEPONIS / POOL / EFE

• Regeneron, the experimental treatment that Donald Trump receives

Donald Trump's covid has brought to light the cocktail of experimental treatments that are trying to curb the infection of the US president. Among them are several compounds that had hardly been heard of and whose effectiveness against the virus is still unknown.

Sean Conley, the president's doctor, has reported that after discovering Trump's infection he injected "as a precaution" a high dose of monoclonal antibodies manufactured by the Regeneron company.

This experimental drug is being tested in hundreds of COVID-infected people and is composed of two antibodies selected for their high capacity to localize and neutralize SARS-CoV-2.

One of them was taken from an anonymous patient who overcame the disease.

The other comes from a type of mouse that has been genetically modified to generate antibodies against the virus that can be injected into people without immune rejection.

These antibodies function like an elite troop trained to locate and eliminate a very specific molecule of the coronavirus: the key it uses to bind to human cells, open them and hijack their biological machinery to produce tens of thousands of copies of itself.

This molecule is known as the receptor-binding domain (RBD) and is part of the pointed spicules that give the virus its medieval mace-like appearance.

If an antibody binds to them before the virus enters the cells, it will block the infection.

In addition to the antibodies - known as REGN-COV2 - the president is taking famotidine, vitamin D, zinc, melatonin and aspirin, according to his doctor.

It has not yet been proven that any of these drugs is effective against covid, although there are indications that they may be and that, above all, they seem safe, according to the experts consulted by this newspaper.

The president of the United States has several risk factors for severe covid: he is a man, older —76 years old — and he is overweight.

At the moment he is admitted to the Walter Reed Military Hospital in Maryland, near the US capital, although his symptoms do not go beyond a moderate fever, congestion and cough.

"For now there is no reason to worry about his health," Conley said today at a press conference outside the hospital where Trump is admitted.

The doctor has revealed that the president is also taking remdesivir, an antiviral of limited effectiveness in the first days of the infection.

The doctor has assured that Trump has been without fever for 24 hours and that he does not need oxygen or artificial respiration.

The Regeneron company is testing the effectiveness of its antibody cocktail both in preventing infections and in treating infected patients.

This same week she announced the first data from one of these trials that include 275 patients who have developed at most moderate symptoms, a state similar to that of Trump, although their average age is 44 years.

Medicinal cocktail

The antibodies reduce viral load by up to 99% and make convalescence last seven days instead of 13. In previous work, the company showed that the cocktail reduces viral load and even prevents infection in macaques and hamsters.

At the moment, neither the animal study nor the clinical data of patients have been reviewed by independent experts or published in a prestigious scientific journal, the golden rule for demonstrating scientific evidence.

The company is going ahead with the trials, in which it expects at least 1,300 people to participate.

Trump has been able to take these antibodies because his doctor has requested them for compassionate use.

Normally, patients can only access this drug if they are included in a clinical trial, but in this case they cannot be sure of receiving the drug, since they can be randomly assigned to the control group that takes a placebo and that is essential to demonstrate the effectiveness of the drug.

The only way to ensure that you receive treatment is by using that legal figure, something that other patients have already been able to do, as explained by George Yancopoulos, Regeneron's chief scientist to

without saying how many.

Making monoclonal antibodies is not easy.

Once isolated from patients and mice, they must be introduced into hamster ovary cells that function as bioreactors to make clones of these proteins.

The average price of these compounds in the US is about $ 100,000 (about 85,000 euros), according to a 2018 study. In July, Regeneron received 450 million dollars from the US Government within the Warp Speed ​​operation to supply about 300,000 Antibody doses before the end of the year in case their efficacy is proven.

Other compounds

The evidence on the rest of the compounds that Trump has been given is much less.

Vitamin D, for example, has been shown to play a protective role in viral infections, explains Ricardo Gómez-Huelgas, physician Ricardo Gómez Huelgas, president of the Spanish Society of Internal Medicine.

"Older people who are deficient in this vitamin have a worse prognosis against infections, but it has not been proven that increasing normal levels has any benefit," he warns.

Something very similar happens with zinc, whose effectiveness against covid has not been proven either.

Famotidine is a drug used against heartburn.

There are preliminary studies done in China that suggest that people who took it had a slightly lower mortality than those who did not take it, but there is no way to know if it was the drug that produced that effect.

In the United States, a clinical trial is underway to study the effectiveness of this compound.

Melatonin is used against insomnia.

Although there is still no evidence of its benefits, it is being studied whether "it can be effective in preventing SARS-CoV-2 infection due to its properties as a powerful antioxidant and anti-inflammatory, being able to modulate and neutralize the negative cellular.

What about aspirin?

Trump's doctor probably didn't give it to him because he expects him to fight the virus, but he did give it one of its side effects: the formation of blood clots that can cause thrombi.

"On the one hand, this cocktail of treatments is a shaman's solution, because there is still no scientific proof of its effectiveness," explains Cristina Avendaño, a pharmacologist at the Puerta de Hierro Hospital in Madrid.

“On the other hand, famotidine, vitamin D, melatonin and zinc are compounds with a very favorable safety profile.

It is not to be expected that they will be very effective, but their toxicity is not high nor is it to be expected that together they can cause complications of the immune system that could aggravate the disease ”, she adds.

Avendaño explains that these drugs are easily accessible and cheap. "There is" a clear risk "that after the announcement people will jump to buy and use them without guarantees and that there will be a shortage, as has already happened with hydroxychloroquine due to the sensational advertisements of Trump.

"The rationale for monoclonal antibodies is very clear," explains Marcos López-Hoyos, president of the Spanish Society of Immunology.

“If the preliminary data on its effectiveness and safety are finally confirmed, they would be a clear alternative until there is a vaccine.

The interesting thing is that according to Regeneron's data, the treatment works better the higher the viral load, with differences of between 90% reduction and 60% ”, he adds.

"What is clear is that Trump has been able to receive the antibodies because he is the president of the United States, any other patient could not have done the same," he highlights.