Profess Luke O'Neill says US doctors have been left "mystified" by the surge in demand for costly COVID-19 antibody treatments from many of the same people who are opposed to vaccines.
US officials have struggled to push vaccination rates beyond the 70-75% mark, with just under 66% of adults fully vaccinated so far.
Some of the very same people who've refused a vaccine have subsequently embraced the extremely expensive and time-consuming antibody infusions instead once they actually catch the virus.
It comes on the back of endorsements from some high-profile conservative figures - and the treatment was used by the then US president Donald Trump when he contracted the virus last year.
The New York Times highlighted the issue in an article over the weekend, highlighting that the growing demand - particularly in southern states - is leading to dwindling supplies of the treatments.
The Biden administration is footing the bill for the treatments, which cost around $2,100 for a single dose and require specialists to administer.
While there's almost universal acceptance that the infusions are an effective treatment, there is some bafflement about why exactly 'vaccine refusers' have embraced this particular treatment.
It's all led to the treatment unexpectedly becoming a major part of some states' response to the pandemic.
Professor O'Neill - Professor of Biochemistry at Trinity College - told The Pat Kenny Show the NYT article is a "fascinating piece of journalism" about an unusual phenomenon.
He explained: “These [treatments are] monoclonal antibodies - Trump took them for example, and Regeneron makes one type. People who won’t take a vaccine are prepared to take these monoclonals.
“But they’d have similar issues if you’re against vaccines - they’re human-made and developed quickly. All the usual criticisms apply to these… and yet the ones denying the vaccines are happy to take the antibody."
Professor O'Neill says the antibody treatments "work great" and are extremely effective.
However, he noted: "They’re a hundred times more expensive [than vaccines], and they take 90 minutes to administer by infusion. You need specialist nurses - it’s a huge drain on resources.
“Drug companies make them, you inject them into your body, and they mop up the spike protein and stop you getting really sick. Then they go away - unlike a vaccine which will protect you.”
Professor O'Neill said the widespread use of these costly treatments is absolutely saving lives, and the US death rate from the virus would be higher without them.
However, he said that the level of demand and apparent contradictions from some of the treatment's advocates has left doctors "scratching their heads".
He observed: “You can’t deny people treatment, obviously.
"But at the same time, the vaccine is cheap as chips - why would you not take the vaccine, as your criticisms would be similar as towards the antibodies?”