The former Clinical Director of the Dublin Midlands Hospital Group is questioning whether young children should get the Pfizer/BioNtech or Moderna vaccines.
Dr Martin Feeley, who is pro-vaccination, is concerned that the risks involved in taking a new vaccine outweigh the benefits of preventing COVID-19.
His concern stems from the fact that the two manufacturers used brand new technology to develop the vaccine.
However, the Chair of the National Immunisation Advisory Committee has disagreed with such concerns - saying young people can still suffer serious illness as a result of COVID-19 and therefore will need to be vaccinated.
Dr Karina Butler said the vaccine development has been "rapid but not reckless or rushed".
She said the process has gone through all the normal stages, but a lot of "unnecessary delays" were removed due to the resources being put into the process.
It comes as Tánaiste Leo Varadkar told his Fine Gael colleagues last night there's a good chance the vaccine roll-out will start by the end of the month.
The European Medicines Agency will meet on Monday to consider whether to give the Pfizer shot the go-ahead.
Speaking on Newstalk Breakfast this morning, Dr Feeley said he believes other coronavirus jabs, such as the Oxford–AstraZeneca vaccine, may be more suitable to young people.
He explained: "The development of a vaccination against COVID-19 is nothing but good and I am not anti-vaccination.
"There is a subset of the population that is very high risk, probably in the order of 1,000 or 1,500 times greater than for the low-risk group which is the young, children and young adults and even people up to the age of 50 who have no risk factors.
"For us doctors, among our primary concerns is to make sure we do more good than harm.
"My concern is that this vaccination could potentially do more harm than good to these very low-risk people.
Dr Feeley said there was a less than one in 10,000 chance of healthy people dying as a result of contracting COVID-19.
He added that the coronavirus vaccine has been fast-tracked to be ready in ten months when other inoculations would typically take ten years to develop.
Two jabs have previously been created through a fast-track process, a swine flu vaccination in 1976 and 2019, with the latter causing "very serious complications for people five to 90 years of age", which includes narcolepsy, he added.
Dr Feeley said: "I'm not going to say this will happen with [the COVID-19 vaccine], but something similar can happen.
"Two of these vaccines that are going to be licensed are completely new biotechnology, processes and production systems never before used."
Treating the roll-out of the vaccine to 100% of the population as a "silver bullet" in combating COVID-19 is wrong and that "nothing could be further from the truth", he said.
People should be free to ask questions, he said, and that the debate comes back to the issue of informed consent.
Dr Feeley added: "What I'm saying is certainly for anyone over 70 and certainly everybody with high-risk factors the vaccination would be a very good idea.
"For very young people and children, it's absolutely not. I would say categorically without any hesitation, children should not be vaccinated with this new vaccine.
"The Moderna and Pfizer [vaccines] are different to Oxford, the Oxford system has been used before so that's probably safer in my mind, it's more proven.
"But for young adults, I would be hesitant."
Young people with long COVID
However, speaking on the same programme, the Chair of the National Immunisation Advisory Committee disagreed with the suggestion that children shouldn't be vaccinated against COVID-19.
Dr Karina Butler said that almost 1,000 people aged 15 to 44 have been hospitalised with the virus and that healthy young people are still suffering from the impact of the virus many weeks after recovering.
She added: "Some of those healthy young people who got COVID are still not over it weeks later in terms of returning to normal activities.
"It's much more than death numbers, it's about the morbidity associated."