Medicines against COVID-19, by Elmer Huerta

Aside from vaccinations, three types of anti-virus drugs have been heard in recent weeks. COVID-19, which we will describe today. One of them, the antiviral molnupiravir –which reduces by 50% the possibility of hospitalization and death in patients who, due to suffering from a predisposing disease, are more likely to be complicated by COVID-19–, was described last week in this column. Today we will see the other two.

—The vaccines—

We have already developed this topic in several previous articles, and we have said that vaccines, like the multiple types of vaccines that humanity has had for dozens of years, are based on

Vaccines belong to various technological platforms. Some – such as AstraZeneca, Johnson & Johnson and Sputnik V – use human or chimpanzee cold viruses as vectors to stimulate the defense system. Others – such as Pfizer / BioNTech and Moderna – use genetic codes from segments of the spike proteins of the new coronavirus to introduce messenger RNA molecules that act in the cell cytoplasm to produce spike proteins and fool the defense system. While others – like Sinopharm and CoronaVac – use chemically inactivated whole viruses to stimulate the defense system.

At the beginning of the vaccination campaigns, it was thought that the vaccines would provide long-lasting protection similar to that provided by childhood vaccines against measles, mumps, or chickenpox, but it appears that the protection of the vaccines is neither complete nor durable. In this regard, two recent studies on the level of protection of the Pfizer / BioNTech vaccine, published in “The New England Journal of Medicine”.

First, done in 4,800 health workers in Israel, measured the levels of neutralizing antibodies against the SARS-CoV-2 and they found that these decreased rapidly after two doses of the vaccine, especially among men, older than 65 years and people with immunosuppression.

“Vaccines were thought to provide long-lasting protection similar to that given by childhood vaccines. […]but, apparently, that protection is not complete ”.

Although it can be assumed that this decrease in the levels of neutralizing antibodies may indicate

The authors say that, in contrast to studies of antibody levels formed in response to measles, mumps, and rubella vaccines, which decline by 5% to 10% each year, antibodies to the new coronavirus decline rapidly and significantly afterward. of the second dose of the Pfizer vaccine.

The study also found that the immune response of people who were vaccinated after having already suffered a natural infection by COVID-19 it lasted much longer than if they were vaccinated without having the infection.

The second, done in Qatar, was an effectiveness study and showed that the protection afforded by Pfizer’s vaccine against symptomatic infection increases rapidly after the first dose, peaks in the first month after the second dose, and then gradually decreases. in the following months. Based on their data, the decline appears to accelerate after the fourth month,. However, and this is very important, the protection against hospitalization and death remained above 90%.

Some experts believe that these studies should alert authorities to be prepared for new waves of disease, even in already vaccinated people.

-Monoclonal antibodies-

Two monoclonal antibody-based drugs have made headlines lately, one from Regeneron laboratory, and the other from AstraZeneca.

Let us remember that monoclonal antibodies are drugs that are obtained by choosing the most effective natural neutralizing antibodies against it. SARS-CoV-2, and then producing them in industrial quantities with various techniques of molecular biology.

Regeneron laboratory has FDA emergency use authorization of the drug REGEN-COV, which is a combination of two monoclonal antibodies, casirivimab (Regn10933) and imdevimab (Regn10987). This is the drug that then-US President Donald Trump received when he fell ill with COVID-19 in October 2020 and is indicated in patients who – due to suffering from a predisposing disease – are more likely to be complicated by COVID-19.

The drug, which is given by intravenous injection in a hospital, has been shown to be

For its part, the AstraZeneca laboratory recently requested authorization from the FDA for emergency use of ambulatory intramuscular injection of AZD7442, its combination of long-acting monoclonal antibodies, tixagevimab (AZD8895) and cilgavimab (AZD1061), which has been reported to have a 77% effective in preventing symptomatic disease in patients infected with the SARS-CoV-2.

The difference between the Regeneron and AstraZeneca monoclonal antibodies is that the latter has modified their molecular structure to make them long-acting, with the laboratory estimating that

Like the Regeneron drug, the AstraZeneca drug should also be administered in patients who –because of a predisposing disease–

In summary, little by little drugs are being discovered that, without a doubt, will reduce the possibility that patients at high risk of complications from COVID-19 will not be hospitalized or die from the infection.

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