Monoclonal Antibodies - Stellar IAS Academy

Last week, an 84-year-old man from Haryana was administered the “famous” anti-Covid cocktail that was also given to former US President Donald Trump.Studies have shown that 80% of patients who took the drug did not need hospitalisation.

Experts here are expecting the antibody cocktail drug for Covid-19 developed by pharmaceutical giants Roche and Regeneron to work effectively in home-isolated mild to moderate patients who are at high risk of developing severe illness. The therapy was granted emergency use authorization in India a couple of days ago. Named ‘REGN-COV2’, the drug is a cocktail of two monoclonal antibodies, Casirivimab and Imdevimab. It is projected to reduce hospitalization by 70%. The drug was tried by former US president Trump after he developed Covid-19 last year.

What are Monoclonal Antibodies?

Human body’s immune system attacks foreign substances by making a large numbers of antibodies. An antibody is a protein that is formed in response to a specific protein on the and sticks to it, the latter referred to as an antigen.

Antibodies circulate throughout the body in the blood plasma until they find and attach to this specific antigen. Once attached, they enforce other parts of the immune system to destroy the cells containing the antigen

Monoclonal antibodies are molecules engineered in the laboratory to serve as substitute antibodies that can restore, enhance, or mimic the immune system’s attack on cells.Scientists can design antibodies that specifically target a certain antigen, such as one found on cancer cells. They can then make many copies of that antibody in the lab that are designed to bind to the selected antigens.These antigens are more numerous on the ‘diseased’ cell than the healthy cell.

It was in 1975 that Cesar Milstein and Georges Köhler developed technique for making monoclonal antibodies.They were awarded the Nobel Prize in 1982.

Monoclonal antibodies are used to treat many diseases, including some types of cancer. To make a monoclonal antibody, researchers first have to identify the right antigen to attack.The first therapeutic use in humans took place in 1982 to treat a lymphoma.

.Monoclonal antibodies are molecules engineered in the laboratory to serve as substitute antibodies that can restore, enhance, or mimic the immune system’s attack on cells.

Antibodies, known as immunoglobulins, are produced by B cells (plasma cells) to neutralize antigens

Scientists are of the opinion that Monoclonal Antibodies will be the bridge toward longer immunity, which will be conferred by vaccines.

What is antibody cocktail therapy?

The therapy is a cocktail of two monoclonal antibodies.
Antibodies are proteins that the body generates to defend itself against any disease. Monoclonal antibodies are artificially created in a laboratory and tailor-made to fight a particular disease.
Normal antibodies in any Covid patient develop only after 14 days of contracting the infection. But in this drug the lab-made antibodies work instantly.
Casirivimab and imdevimab, which are part of the antibody cocktail produced by Switzerland-based Roche, are specifically directed against the spike protein of SARS-CoV-2, which causes Covid.
They block the virus’ attachment and its subsequent entry into human cells. Use of two antibodies protects against the body’s resistance to them.
An antibody cocktail is administered intravenously or subcutaneously (under the skin) as an injection.

A triple combination drug — repurposed Interferon Beta-1b with Lopinavir-Ritonavir and Ribavirin — is also projected to reduce Viral Load.

Researchers is the western world are strongly pushing for yet another combination,Eli Lilly’s Bamlanivimab and Etesivimab,

Pros of Monoclonal Antibody Therapy:

1.They are quicker to develop to target a disease than vaccines.

2.They function rapidly.

3.Their safety is theoretically easier to predict

Cons:

1.Higher cost especially when sufficient product is needed to evoke response.

2.Time consuming – any where between 6 months -9 months.

3.Very expensive and needs considerable efforts to synthesize them.

Steps in Production of Monoclonal Antibodies:

Monoclonal antibodies (mAbs) are produced by injecting an antigen to a mouse, which causes production of antibodies by it’s immune system and then fusing polyclonal B cells from the mouse’s spleen to myeloma cells. The resultant hybridoma cells are cultured and they continue to produce antibodies to the antigen.

What are Polyclonal Antibodies?

Whereas monoclonal antibodies come from a single cell lineage),polyclonal antibodies are secreted by different B cell lineages within the body.

These are a collection of immunoglobulin molecules that react to a specific antigen, each identifying a different epitope and can recognize and bind to many different epitopes of a single antigen.

Polyclonal antibodies are produced by injecting an antigen into an animal. To produce higher titers of antibodies against the particular antigen, the animal is given a secondary even tertiary immunization, after being injected with a specific antigen to elicit a primary immune response.

Polyclonal antibodies can now be obtained straight from the serum or purified to obtain a solution which is free from other serum proteins.

Important Topics Prelims 2020