Professor Luke O'Neill says some of the recent news and developments around the Johnson & Johnson COVID-19 vaccine have been very reassuring.
The Trinity Professor says trial results show it has good efficacy in preventing severe disease linked to the South African variant of coronavirus.
He also said there's now a treatment for the extremely rare blood clotting reported in some people who've received both the Johnson & Johnson and AstraZeneca jabs.
It comes as members of NIAC are meeting this morning to consider what advice to give the Government on the Johnson & Johnson COVID-19 vaccine.
Tánaiste Leo Varadkar has said he hopes NIAC's advice will be that those under 60 can get the single-dose vaccine.
The AstraZeneca vaccine is currently limited to 60-69 year-olds due to concerns over the very rare incidences of blood clotting.
Professor O'Neill told The Pat Kenny Show it will be 'tremendous' if NIAC signs off on the use of Johnson & Johnson vaccine.
He said: "It’d be a huge add on. I keep saying this: it is about speed, and we want to get the vaccine out as quickly as we can for all kinds of reasons - not least to release us from this period we’ve been in.
“They might allow it for the over-30s… in the UK they’ve allowed the AstraZeneca vaccine for the over-30s.
“That’s our hope… but we don’t know. They’re weighing everything up: it’ll be a fascinating meeting they’re having, I predict. There’s bound to be a diversity of opinions."
'We should use it as widely as possible'
Ireland's due to get around 605,000 doses of the Johnson & Johnson jab this quarter, with the first deliveries having already arrived.
One key question is whether NIAC will sign off on the use of J&J in younger cohorts while restricting the use of AstraZeneca.
However, Professor O'Neill said there are two possible justifications for health officials on that front.
He explained: "AstraZeneca’s supply is uncertain… we keep hearing this. Yet we have loads of J&J coming in, so we should use it as widely as possible.
“The second [thing] is really good news yesterday. A woman with this very rare clotting disorder… was treated successfully in hospital with IVIG [intravenous immunoglobulin]. We knew this was coming.
“This woman had symptoms of clotting after the vaccine… bruising, little blood clots in her skin.
"She went to hospital… they treated her, and she was discharged very quickly.”
He said the odds of clotting are 'almost vanishingly rare' - although it's understandable people are anxious when they hear the reports about it.
However, he said: “Now we know it can be treated, and that means you can be even less worried about it.”
The leading immunologist said the particular type of rare clotting in question is more of a danger (although still rare) from COVID-19 itself.
He noted that people are “five times more likely to get these very, very rare clots by being infected with the virus than from the vaccine".
Professor O'Neill said there are now more reasons to be reassured about the Johnson & Johnson jab now thanks to news around the clotting treatment, as well as efficacy rates when it comes to variants.
He noted that "we were always pretty reassured about AstraZeneca anyway".
He said: “I wouldn’t have any qualms about taking AstraZeneca if I was offered it. It’s giving you 100% protection against severe disease and death.
“If you’re offered Johnson & Johnson, take it: it will give you great protection for several months into the future. Maybe you’ll take a booster in the future… in the autumn, or whenever that may be.”
He urged people not to get 'hung up' about the higher efficacy being reported for the mRNA Pfizer and Moderna vaccines - saying scientists are very happy with all the vaccines currently approved for use here.
Professor O'Neill said he sympathises with those over-60s who are only being offered AstraZeneca and might have concerns around it - although said it's "just the situation we’re in" due to issues around supply.