There are currently no vaccines to prevent infection with SARS-CoV-2, the virus that causes COVID-19. Although at least one clinical trial of an investigational vaccine is currently underway, the release of such a vaccine could take months or even years. Scientists at DARPA, the Defense Advanced Research Projects Agency, are working to develop a therapeutic strategy against SARS-CoV-2 using monoclonal antibodies.

Antibodies are proteins that identify pathogens for destruction by the immune system. They arise from different cell lineages and bind to multiple epitopes – regions on viral proteins to which immune cells bind to drive a targeted immune response. Monoclonal antibodies, on the other hand, are made by identical immune cells cloned from a single, unique parent cell. They bind to a single, specific epitope.

DARPA’s research is part of the Pandemic Prevention Program, or P3. Their goal is to determine which monoclonal antibodies the body produces when it encounters a particular virus, such as SARS-CoV-2, and then stimulate the body’s production of those antibodies. The process involves sequencing the RNA of B-cells taken from a person who has recovered from a particular pathogen and then producing antibodies against the pathogen. The antibodies can then be injected into a healthy person to promote immunity or injected into a sick person to facilitate recovery.

This strategy can serve as a sort of stopgap measure until a vaccine is developed. Although identifying and producing these antibodies is a lengthy process, DARPA is working to facilitate discovery and accelerate capacity to produce the antibodies at scale.

• Read this review of COVID-19 monoclonal antibody research for more information.