It is unknown how US President Donald Trump will respond to the experimental immunotherapy given to treat his COVID-19 infection, because the drug has not yet been tested and approved, says Hudson Institute Director and CEO, Professor Elizabeth Hartland.
President Trump was diagnosed with COVID-19 last week and hospitalized on the weekend at Walter Reed National Military Medical Center, where doctors infused him with an experimental drug, Regeneron's REGN-COV2. He has also since been administered with remdesivir, an antiviral, and dexamethasone, a corticosteroid, plus zinc and vitamin D.
Interviewed by ABC News Channel on the weekend, Prof Hartland said the 'antibody cocktail', REGN-COV2, given to the President, had not yet been fully tested.
"Regeneron has developed two very specific immunotherapies, antibodies, and these target the so-called spike protein of the virus," Prof Hartland told host, Jeremy Fernandez.
"That's the part of the virus that it uses to attach to human cells. Once it is inside the cells then it starts to multiply. The idea is that these antibodies can block the spike proteins from attaching to the cells and thereby prevent the virus getting into cells in the first place.
"We don't know how effective this drug will be," Prof Hartland said. "It has been tested in around 275 people and the average age in that clinical trial was 44, so that is quite different to Mr Trump.
"Those investigators were able to show a lower viral load and also shorter time to recovery, but in any individual, it would be very hard to predict what is going to happen."
Prof Hartland said the President is already in a high-risk category because of his age, weight and gender.
"We know from all the studies that have been done around the world and how people are affected by this virus that in people of older age, in people who have underlying heart disease or co morbidities, like diabetes, or they are overweight, or male gender, they're much more likely to experience severe complications with the coronavirus.
"So he's already in a high-risk group and it may be that the trial group doesn't match these criteria. It will be a bit of an unknown how he will respond to this therapy."
The next few days are expected to crucial for President Trump, because, depending on the timing of his infection, symptoms can either worsen or improve in the second week.
"Generally, around day eight or nine things can start to go downhill," Prof Hartland said. "That's when the immune response starts to really ramp up and people can begin to develop the life-threatening inflammation which leads to acute respiratory distress. It depends a little bit on how long Mr Trump has been infected. I'm sure his doctors will be very cautious over the next few days to keep an eye on that."
President Trump was said to also be taking vitamins. "Again, I don't think that we can predict with any certainty how that is going to play in, because we haven't done clinical trials on zinc and vitamin D and how these impact people's response to the coronavirus. So really, he's in a very experimental situation," Prof Hartland said.
