As most everyone knows, President Trump and the First Lady were recently diagnosed with COVID-19. President Trump was using an experimental antibody drug cocktail (REGN-COV2) manufactured by Regeneron Pharmaceuticals to speed up his recovery, as discussed by Dr. Thomas Campbell, an infectious disease specialist at the University of Colorado School of Medicine. In his article, Campbell asserts that REGN-COV2 contains two monoclonal antibodies. He describes monoclonal antibodies as lab-engineered proteins that act like the effector cells of the immune system that are normally naturally produced at exposure to a viral infection. Regeneron decided which antibodies to use as monoclonal antibodies by observing antibodies that were present in human patients that recovered from COVID-19, as well as in mice that were genetically engineered to have human-like immune systems. The findings of their observations led the researchers to two key antibodies, where were manufactured into the monoclonal antibodies REGN10933 and REGN10987 that are used in the REGN-COV2 treatment. Both of these antibodies bind to different segments of the SARS-CoV-2 glycoproteins, which hinders the ability for the virus to enter human cells and replicate.
Monoclonal antibodies mimic the action of naturally made human antibodies in the immune system. They can be made from either mouse proteins, human proteins, or a combination of the two, as discussed in this article by the American Cancer Society. They can be useful in treating a variety of diseases, including even cancer! The process of making a monoclonal antibody first requires researchers identifying the correct antigen to target for attack. After this has been determined, they can make copies of an effective antibody in the lab by cloning a single B-cell. Since this antibody comes from a single B-cell and targets a single epitope, it has been coined as a “monoclonal” antibody.
Trump’s monoclonal antibody therapy utilized the method described above and involves the action of two monoclonal antibodies, as discussed previously. Media outlets described his therapy as being made from fetal stem cells, which got a lot of attention from the public due to Trumps political affiliations; however, this was a false claim that carried on much further than it should have. In a fact check by USA Today, Alexandra Bowie of Regeneron told the media that REGN-COV2 is, in fact, not made from human embryonic stem cells. Bowie goes on to say that position statements on the use of embryonic stem cells by Regeneron are for transparency purposes and that their statement was a general position statement of their company in general, not specific to the method used for this particular drug. The specific cells used to isolate the antibodies generated for this drug actually came from a B-cell line isolated from human donors and mice that were genetically engineered to have human immune systems. Another area of confusion in regards to the use of stem cells was Regeneron’s use of HEK293T cells (an immortalized epithelial cell line), which were briefly used to create SARS-CoV-2 like viral particles to test the monoclonal antibodies. Bowie affirmed that HEK293T cells were used, but held her position that embryonic/human stem cells were not involved in the production of REGN-COV2.
As discussed in the introductory paragraph, the monoclonal antibodies used in REGN-COV2 target the glycoprotein spike of the SARS-CoV-2 virus to inhibit the virus from being able to enter the host cell and replicate. These types of drugs are designed to treat existing cases of infection, not to prevent future cases of infection. Due to the nature of the drug and the mechanism of its action, I would venture to say that these synthetic antibodies will not provide future immunity since they are already antibodies. Antibody therapy can treat an existing infection but will provide no long-term immunity. To me, ithis concept can be analogized to “if you give a man a fish, he’ll eat for a day; but if you teach a man to fish, he will eat for his whole life.” If we provide our body with the necessary antibodies to fight off infection (“give” ourselves the antibodies), we will have what we need to fight the current infection. However, if we teach our bodies to generate their own antibodies and memory cells, then our body will be able to better protect itself in the future. Hopefully, a generation of a vaccine in the near future will be able to help provide the latter very soon.