The Emergence of Polyclonal Antibody Treatments for COVID-19

virus

Early in the development of a treatment for COVID-19, monoclonal antibody treatments worked well. These treatments are laboratory-engineered proteins that are designed to imitate the body’s immune system and its ability to battle destructive pathogens, such as SARS-CoV-2. Ultimately, viruses have a tendency to evolve, and with the onset of the Omicron variant, they have proven ineffective. The virus’ natural ability to mutate is the reason that the virus continues to adapt to treatments.

Monoclonal Treatment 

Monoclonal antibody treatments are engineered to attack one specific area of the virus – the spike protein. In doing so, the virus is blocked from entering a cell through that protein and damaging it, which subsequently halts the spread of the infection through the host body. But since the monoclonal antibody treatment only targets a single area of the virus, any mutations in the area will make the treatment ineffective. 

Since the onset of the Omicron variant, monoclonal treatments have waned as an effective means to fight the virus, and new methods have been needed to combat the disease. Now, there are new polyclonal antibody treatments, which target and attack multiple areas of the virus, including the Omicron variant. 

Omicron Variant 

Following the Delta variant, which emerged in late 2020, the Omicron variant rapidly became the de facto variant infecting the US population. The CDC now estimates that 99% of all new cases of COVID-19 are of the Omicron variant, effectively rendering monoclonal antibody treatments obsolete in nearly all cases. This has caused medical professionals and researchers alike to find a new method of treating the disease. 

In January 2022, polyclonal antibody treatments began Phase 3 of research at the University of Texas Southwest Medical Center in Dallas. They began enrolling patients that fit the right criteria for the study. The criteria included individuals who were middle to elderly in age, unvaccinated, and/or immunocompromised people. 

Polyclonal Treatment

Currently, the National Institute of Allergy and Infectious Diseases (NIAID) has begun enrolling human subjects for Phases 2 and 3 in a study called ACTIV-2 for SAB-185, a polyclonal antibody treatment that has successfully passed Phases 1 and 1b, where the treatment was found to have demonstrated neutralization of live SARS-CoV-2 at titers higher than convalescent plasma. This means that SAB-185 showed that it could counteract the virus at a higher rate than by using a sample of a convalescent patient’s blood via Convalescent Blood Therapy – a method by which medical professionals introduce the antigen directly into a currently infected patient in the hopes that the infected patient’s immune system will begin to emulate the antigen introduced by the blood sample. 

With one mutation already rendering the bulk of COVID-19 treatments obsolete or less effective, it is imperative that the shift from monoclonal antibody treatments to polyclonal antibody treatments be fully studied and a new way forward in consistently treating the disease be found as soon as possible.