Clinical data proving the AstraZeneca vaccine is effective in older people could be available by the time the first doses arrive in Ireland, according to Trinity Professor Luke O’Neill.

It comes after the health officials were advised to offer the elderly the Pfizer or Moderna vaccines where possible.

The National Immunisation Advisory Committee (NIAC) all three currently approved vaccines are suitable for use for all ages – but said Pfizer and Moderna should be offered to over-70s “where practicable and timely.”

The recommendation is based on the fact there was a limited number of elderly people included in the originally AstraZeneca clinical trials.

On The Pat Kenny Show this morning, Trinity Professor Luke O’Neill said a new trial involving 20,000 patients of all ages is due to report soon.

“It is arriving in Ireland in about two weeks so, by the time we have the AstraZeneca doses in the country, I am hoping that data will be released,” he said.

“But we can predict the results by the way because the Phase Two trial showed that this gave a very good response in older people – therefor we are confident it should work in older people.

“The trouble is they had very few older people in the trial. It was slight mis-step for them actually. They should have had more old people in the trial.”

Elderly

He said his personal prediction is that the jab will be shown to be efficacious for young and old but admitted that for now, “the data just isn’t there yet.”

“It does make sense to use up the Pfizer vaccine on those older people where the evidence is with older people,” he said. “But I bet, ultimately, this vaccine will be used in older people just like the Pfizer one.”

Professor O’Neill said the big news coming out of AstraZeneca is new data showing that it is effective in terms of stopping transmission of the virus.

Transmission

Up to now, clinical trials of all the vaccines on the market have shown them to be capable of preventing illness; however, up to now it has not been clear how effective they are at stopping people from passing it on to others.

“This is the first time we have seen scientific evidence if you like that is really robust suggesting this particular vaccine stops transmission,” he said.

“What it shows is that, if you are vaccinated with AstraZeneca, you have a 67% decreased transmission rate.

“In other words, they took swabs from people who are vaccinated and there was much less virus in their noses than the ones who weren’t, so there was much less virus to spread.

“Overall, that vaccine now is predicted to slow down spread by 67% which is substantial. That will take a lot off the R number then obviously because the virus spreads a lot less on this vaccine.

“This is the first indication of that so it is very welcome. It is the first time that has been shown in a trial.”

On Newstalk Breakfast this morning the Chair of the National Immunisation Advisory Committee Professor Karina Butler said every vaccine that works "is going to find its place” in Ireland’s vaccination programme.

Vaccine doses

Professor O’Neill said there is also new evidence to suggest the AstraZeneca jab is more effective if you wait a longer time between doses – a finding that could have a significant impact on how quickly it can be rolled out.

“They just published a big trial,” he said. “So, there was 76% efficacy with a single dose – which is very high.

“When they gave a second dose after three months, they got 82.4% efficacy.

“That three-month gap sems to be important. With less than six weeks of a gap it was only 54% efficacious so leaving it three months really boosted the efficacy.

“So, one question I have is whether we should wait three months for the second shot when we use that vaccine in Ireland.”

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