Are monoclonal antibodies the queen of the game against covid-19?

The negative results of the Solidaridad trial have recently been confirmed. The essays of the Four treatments evaluated (remdesivir, hydroxychloroquine, lopinavir / ritonavir and interferon) have shown little or no effects, both at the level of general mortality, as in the time elapsed until the initiation of mechanical respiration or the duration of hospitalization in admitted patients.

In addition to antivirals and anti-inflammatories, other compounds have been studied, such as vitamin C and colchicine. Unfortunately, as we see in the table, the results of the trials have not been very encouraging.

Nor is the plasma treatment of survivors, which emerged as the first fast and affordable therapy, is valid. The risks it entails have ruled out its use.

Monoclonal antibodies, the definitive therapy?

But we still have chips on the board to fight back. Of the 319 trials of compounds currently against COVID-19, 80 studies correspond to antibodies as therapeutic agents. About a dozen are already in phase III, and as many in phase II. This means that they are very close to their final approval.

Antibodies (also known as immunoglobulins) are Y-shaped proteins (figure 1) that float in the blood and are capable of sticking (binding with high affinity) to a protein from a bacterium or virus (called an antigen). The pathogen is thus deactivated or marked so that the rest of the immune system can detect and destroy it.

Antibodies are secreted by so-called plasma B cells, which appear in the blood when an infection begins. Each antibody is specific for an antigen. Much of the structure is common to all of them, but there are small areas at the upper ends of the Y, called variable regions, which are distinct and specifically recognize various pathogens.