Laboratory-made clones (copies) of a single antibody that works like natural antibodies do.
Monoclonal antibodies for SARS-CoV-2 lock onto the virus directly, making it unable to enter cells. They can also be designed to bind to substances that modulate the immune response, such as cytokines, and can shut down damaging inflammatory responses as witnessed in severe COVID-19 cases. There are on-going clinical, incomplete trials of a cocktail of two monoclonal antibodies for use in COVID-19 patients.
These synthetic antibodies have been used to treat cancer as they can bind to cancerous cells and prevent them from multiplying. The complexity of isolating the specific antibodies from the blood and then growing many copies of them in the laboratory makes this treatment very expensive. Without the research and development costs, a gram of monoclonal antibodies could sell for between US$100 to US$200.
Immune System Infectious Disease Treatment