New Delhi: On October 2, the White House announced that US President Donald Trump, who is being treated for Covid-19, had been administered eight milligrams of the pharmaceuticals company Regeneron’s experimental therapy comprising two monoclonal antibodies.
“It is called a cocktail because it’s a mix of two sets of antibodies…So it’s a bit like a one-two punch, both these fellows go, and they do the same thing. And they, they, they work towards the same objective,” ThePrint’s Editor-in-Chief Shekhar Gupta said in episode 587 of ‘Cut The Clutter‘.
In the episode, Gupta explained what the antibody cocktail constitutes, how it works, and the challenges the therapy poses.
What is the antibody cocktail?
Gupta explained how the antibodies work using a military analogy. “It’s like soldiers moving on the ground and taking care of any adversary who’s there, and then others going on the helicopter and looking at those from a distance and shooting them up,” he said.
He explained how people’s fears that immunity to Covid lasts for three to four months is just based on a fallacy since our bodies have immunological memory. He particularly pointed to the thymus cells and the B cells that are responsible for humoral immunity.
“That immunological memory resides in memory T cells and memory B cells. Memory T cells have a shorter memory, memory B cells have a longer memory,” he said. Regeneron’s antibody cocktail was made using these B cells taken from people, who had contracted Covid-19. “What they do is they don’t activate the body’s immune system to fight the virus that the vaccines do,” Gupta added.
How it works
The coronavirus, according to research, infects the host cells using its spike proteins. This uses ACE2 receptors or angiotensin-converting enzyme 2 receptors, the enzyme attached to the cell membranes of organs like the lungs, arteries, heart, kidney, and intestines, to enter the body.
Gupta explained the two functions of the cocktail. “One, it functions by binding itself to the receptor-binding domain of the spike protein,” he said. In this case, the virus is unable to bind with the receptors.
“The other route is it goes and blocks the ACE2 receptor. So if the receptor is also blocked, and this is also blocked…If it cannot go and attach itself then the coronavirus would die,” he further added.
Although seemingly effective, the therapy hasn’t been tested in big enough trials to sufficiently prove its safety and efficacy yet.
Also read: Covid was a ‘blessing from God’ as it gave him antibody drug experience, Trump says
The ‘first blow’
Gupta further elucidated that the monoclonal antibodies are immune cells that have been cloned from a unique parent cell, in this case, a neutralising memory B cell. “So, initially, they took it from a sick patient who had recovered, obviously a volunteer and then they cloned,” he said.
He then went on to explain the more “striking” aspect of the research behind the antibody cocktail, which he called a “blow struck for science”. “They (the researchers) then thought that you know, to collect it from so many people and to find it would be cumbersome. Plus, it’ll take you a long time to scale up. So they thought why not try it in mice, which mimic the human immune system,” he explained.
The genetically modified mice were then used to produce the B cells. He, however, highlighted that since mice are used to produce the antibodies the procedure involved is “cumbersome and expensive”. “And the treatment remains confined to very few people…So if it’s all the world’s needs, it will take forever,” he said.
The antibody cocktail also presents another catch. “It does not work so well on patients who’ve already started producing antibodies to fight Covid. But it works much better on patients who have not yet started producing the antibodies,” Gupta highlighted.
This means that the therapy, which is otherwise not affordable for most people, will also be ineffective unless administered in the very early days of the infection.
Also read: Antibody cocktail given to Trump is controversial, and not only because it’s still under trial
The second ‘blow’
Gupta concluded the episode by pointing out the “hypocrisy” of the Trump administration. A member of the conservative Republican party, which has an anti-abortion stand, Trump had last year placed curbs on embryonic stem cell research.
The same antibody cocktail that Trump was administered used embryonic stem cells produced through in-vitro fertilisation. “But once again, the hypocrisy of the anti-science people has been exposed because Donald Trump is seeking votes in the name of being pro-life, but is quite happy to take a drug based on embryonic stem cell research,” Gupta said while describing this as the “second blow struck on behalf of modern science”.
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