Independent.ie, DCU Professor of Immunology Christine Loscher said protection against Covid-19 for Janssen recipients could now be as low at 10-15pc.
In a message posted on Twitter this week, the country’s deputy chief medical officer, Dr Ronan Glynn, wrote: “Incidence has begun to rise sharply in those aged 16-34 yrs. This will spread in the coming days to affect other age groups.”
Prof Loscher said this is further proof that Janssen recipients in this age group should be prioritised and she argued that this “has been highlighted for weeks now”.
She said data on the Janssen vaccine has shown that people who took the jab now have “practically no immunity”.
“We were calling a few weeks ago to say that this was a group that were almost going to look like a group that were unvaccinated, particularly against this new variant.
“They probably have as low as 10-15pc protection left. Their immunity wanes a lot faster than the other vaccines and went a lot lower than the rest of them,” she explained.
Prof Loscher argued that people in this age cohort “queued around the corner” for the Janssen vaccine when it was announced that it would not be given to people aged over 50 years.
“We couldn’t have known that their immunity would wain so fast and in light of the fact that Omicron is dominant and highly transmissible, they practically have no immunity against Omicron and I think for that reason they should be at least allowed go to walk-ins (vaccination centres),” she added.
People aged 16-34 years can currently only get vaccines if their GP can prioritise them.
Prof Loscher said she does not want to create an “either/or” scenario for vaccines prioritisation but she pointed out that while walk-in centres have been “overrun” in general, “we see on social media that at certain walk-ins during certain times of the day, there are actually no queues”.
The call to expand walk-in clinics beyond their current capacity has been echoed by UCC Immunovirology Professor Liam Fanning.
He also argued that more "younger people” are now being infected because their vaccine efficacy is waning and said the prevalence of infection among this cohort is reflective of the situation at the start of the roll-out when older people were vaccinated first.
“Once the over-50s were done I think we had largely covered those that were going to have consequences as a result of waning immunity and picking up this infection,” he told
“With the third shot, yes I think we should have opened it up and I think it’s not too late,” he added.
Meanwhile, head of the Behaviour Research Unit at the ESRI, Professor Pete Lunn, said different age groups are complying with restrictions to the same degree.
Speaking on RTÉ’s
Today with Claire Byrne programme he said: “You hear it assumed all the time that younger people are much more socially active than older adults, that actually really isn’t true.
“The thing is that younger people are more visible and that’s one of the reasons why we’re overestimating their social activity.
"Older people are much more likely to be socialising in other people’s homes and that’s not visible but as we know from how this disease transmits, that is one of the places that you’re really quite likely to pick up the disease,” he added.
Prof Lunn said the risks people are willing to take are connected more closely to their personality type than to how old they are.
He said that “you have to feel for the younger people” because they are catching the disease at a higher rate because most of them have not been boosted yet.
“Yes, it is the case that young people are more likely to pick it up but it’s not only to do with their behaviour, it’s very much to do with the fact that they’re less likely to be vaccinated and have had that third jab which we can see is really important,” he said.
Prof Lunn added that it is very important not to blame younger people and said ESRI data shows they are “bearing the brunt” of the pandemic in terms of “mental health” and “loneliness”.
“You might assume that the oldest people in our society are the most lonely - that turns out not to be true at all. Actually, the people during this pandemic who are most expressing loneliness are aged 20-30 and they’re also the people who are most likely to say their mental health has deteriorated since the start of the pandemic,” he said.