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Therapy based on antibodies better way than vaccine to fight COVID?

Manufacturers not needing a steady supply of antibody-rich blood to produce monoclonal antibodies makes this therapy easier to scale up

Many scientists and researchers believe a therapy based on antibodies would be a better approach to treating people infected with the coronavirus disease (COVID). This, even as some potential vaccines have emerged in the worldwide race to find the right medicine that can fight the pandemic.

An infected human being or animal generates many an antibody when a foreign body (for example, a bacterium, a virus or a parasite) attacks, which is the principle behind these therapies. Scientists discovered this biological phenomenon in the late 19th century when they used a serum drawn from the blood of infected animals to treat diphtheria.

For COVID-19 treatment, researchers trying to find out the use of convalescent plasma and other treatments by studying the blood of recently recovered patients. Of late, scientists have developed treatments called monoclonal antibodies. They can isolate these antibodies and even manufacture them in large quantities to treat diseases like Ebola or cancer.

Eli Lilly and Co, Regeneron Pharmaceuticals and other pharmaceutical firms in the US using this approach to develop treatments for COVID.

Fortunately, manufacturers do not need a steady supply of antibody-rich blood — unlike in the case of convalescent plasma — to produce monoclonal antibodies. Hence, this therapy is easier to scale up.

Therapy based on antibodies different from vaccines

The objective of a vaccine, generally speaking, is to generate an immune response that can prevent someone from falling ill. Antibody-derived products, on the other hand, treat disease. However, some vaccines can act as medicines too.

Whereas some pharmacologists suggest an antibody therapy can be used prophylactically, it could be expensive. Regeneron’s Chief Scientific Officer George Yancopoulos said the company’s therapy could be a bridge to a vaccine.

“You might go into nursing homes or the military and use it because antibodies have a pretty long half-life,” said Dr Betty Diamond, Director of Molecular Medicine at the Feinstein Institutes for Medical Research, adding, “You might decide that you are going to use this as prevention in this very high-risk group, but you wouldn’t do that for the whole country.”

Explains Feng Hui, chief operating officer at Shanghai Junshi Biosciences, “The amount of protein in antibody drugs makes the treatment more expensive than vaccines in general.”

On the positive side, an antibody-drug contains hundreds or even over a thousand times more protein than what is found in a vaccine shot.

Geneticist-turned-pharmacologist Chaitali Bhattacharjee prefers a vaccine, though. She told Sirf News, “Viral vaccines are created on the basis of immutable parts of the virus and, hence, have a higher chance of targeting COVID. Therapeutic drugs will take longer to develop. Only by name, these are vaccines. They work like medicinal drugs.”

Developers of the antibody therapy

Eli Lilly is collaborating with Junshi and Canadian biotech firm AbCellera Biologics to develop different antibody treatments, both of which have started early stage testing in humans.

Regeneron plans to launch its clinical studies later in June to test its antibody cocktail treatment. The firm derived it from antibodies developed in genetically-modified mice. It aims to have hundreds of thousands of preventative doses available “by the end of the summer or the fall.”

Bringing together Japan’s Takeda Pharmaceuticals and CSL Behring, the COVID-19 Plasma Alliance is working on hyperimmune globulin therapy derived from convalescent plasma. This could offer a standardised dose of antibodies. It need not be limited to patients with matching blood types.

The Antibody Therapy Against Coronavirus (ATAC) project, which the European Commission funds and Sweden’s Karolinska research institute leads, is looking at a similar approach as well as a therapy based on monoclonal antibodies.

Under the project, scientists are testing monoclonal antibodies extracted from convalescent plasma on human volunteers in Germany and on animals in Switzerland.

Britain’s GlaxoSmithKline is working with Vir Biotechnology Inc to develop potential antibody treatments which select the best antibodies out of the plasma.

AbbVie has announced a collaboration to develop an antibody therapy too.

Singapore’s state research body A*Star is working with Japan’s Chugai Pharmabody Research on an antibody for clinical use.

By Indranil Mazumder

Science writer and teacher

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