Researchers at Columbia University Irving Medical Center (United States) have isolated antibodies from several patients with COVID-19, which to date are among the most potent in neutralizing the SARS-CoV-2 virus.
These antibodies could be produced in large quantities by pharmaceutical companies to treat patients, especially in the early stages of infection, and to prevent infection, particularly in the elderly.
“We now have a collection of antibodies that is more powerful and diverse compared to other antibodies that have been found so far, and they are ready to be developed into treatments,” explains the work leader, David Ho, scientific director of the Research Center. Aids Aaron Diamond and professor of medicine at Columbia University College of Physicians and Surgeons Vagelos.
In their work, published in the journal Nature, researchers have confirmed that their purified and strongly neutralizing antibodies provide significant protection against SARS-CoV-2 infection in hamsters, and are planning more studies in other animals and people.
One of the main responses of the human body to an infection is to produce antibodies, that is, proteins that bind to the invading pathogen to neutralize it and mark it for destruction by cells of the immune system.
Although several drugs and vaccines in development for COVID-19 are in clinical trials, they may not be ready for several months. Meanwhile, the neutralizing antibodies to SARS-CoV-2 produced by COVID-19 patients could be used to treat other patients or even to prevent infection in people exposed to the virus. Developing and approving antibodies for use as a treatment usually takes less time than conventional medications.
This approach is similar to the use of convalescent serum of COVID-19 patients but potentially more effective. The convalescent serum contains a variety of antibodies, but because each patient has a different immune response, the antibody-rich plasma used to treat one patient may be very different from that given to another, with concentrations and concentrations neutralizing antibody variables.
Ho’s team found that although many patients infected with SARS-CoV-2 produce significant amounts of antibodies, the quality of those antibodies varies. In the patients they studied, those with severe diseases requiring mechanical ventilation produced the most potent neutralizing antibodies.
“We think that the sickest patients saw more viruses and over a longer period of time, allowing their immune systems to mount a more robust response. This is similar to what we have learned from the experience of HIV,” says Ho.
Most anti-SARS-CoV-2 antibodies bind to the spike glycoprotein, a feature that gives the virus its crown, on the virus’s surface. Some of the more potent antibodies were directed to the receptor-binding domain (where the virus binds to human cells), but others were directed to the N-terminal region of the tip protein.
The team found a more diverse variety of antibodies than previous efforts, including new and unique antibodies that were not previously reported. “These findings show which viral spike sites are most vulnerable. Using a cocktail of different antibodies that target different sites on the spike will help prevent the virus from becoming resistant to treatment,” the scientist argues.