We need your help now

Support from readers like you keeps The Journal open.

You are visiting us because we have something you value. Independent, unbiased news that tells the truth. Advertising revenue goes some way to support our mission, but this year it has not been enough.

If you've seen value in our reporting, please contribute what you can, so we can continue to produce accurate and meaningful journalism. For everyone who needs it.

Dr Ronan Glynn, Acting Chief Medical Officer, Department of Health and Professor Karina Butler, Chair of National Immunisation Advisory Committee (NIAC) Sasko Lazarov/
rare blood clotting

Q&A: Why Ireland changed its guidelines for the AstraZeneca vaccine - and how it'll affect the rollout

The HSE is going to consider over the next few days how this affects the vaccine rollout.

SENIOR HEALTH OFFICIALS answered questions last night about the implications of new advice on the administration of the AstraZeneca vaccine would have on Ireland’s vaccine strategy and the lifting of Covid restrictions.

NIAC has recommended that the Oxford-AstraZeneca vaccine be given only to people aged over 60 after reports of rare blood clotting events emerged.

Those rare blood clotting events occur in 4-10 cases in every million AZ vaccine doses administered, in which one person may die.

The HSE has cancelled AstraZeneca vaccine appointments due from today onwards, and is to consider how the announcement will affect the vaccine rollout over the coming days.

Here’s what we know so far.

The risk of blood clots versus the risk of Covid

20210412_201551 A graph comparing death (red) and ICU admission (blue) from Covid with the rare clotting side effect (yellow) from the Oxford-AstraZeneca vaccine. Gráinne Ní Aodha Gráinne Ní Aodha

Outlining the decision to limit the use of the vaccine to over 60s only, NIAC chair Professor Karina Butler said last night that someone aged 60-64 was 85 times more likely to die of Covid-19 than to have any clotting event from the vaccine – that includes all clotting events reported, and not just the rare thrombosis.

People aged 55-59 are 48 times more likely to die of Covid-19 than get a blood clot.

Among the 20-30 age group, the risk of dying from Covid was twice as likely, than to develop any clotting event related to the AstraZeneca vaccine, with the latter as a worst-case scenario.

Butler added that these figures only covered the most extreme possible result of contracting Covid-19, death, and didn’t take into account the “burdens” of Covid: the likelihood of getting hospitalised or being admitted to ICU with Covid, or the long-term effects of Covid-19, also known as long Covid.

The overall risk is taken from the EU regulator, the European Medicines Agency (EMA) and the UK regulator, the Medicines and Healthcare products Regulatory Agency (MHRA). The Covid risk figures are taken from the Irish data on Covid-19. 

Dr Niamh O’Connell also pointed out that of Covid-19 patients who are hospitalised, 8% experience clotting, and 27% of those who go into ICU could get a clot – though it was stressed that these were different clots to the rare ones linked to the AZ vaccine.

So can only 60-69-year-old get the AstraZeneca vaccine now?

No. The AstraZeneca vaccine was approved for use for the whole population before being limited to only under 70s over concerns about clinical trials not having enough data of the vaccine in over 65s.

However, those reports were subsequently reviewed and AstraZeneca was rolled out to over 70s again.

Professor Karina Butler said that on an operational basis, people aged over 70 have continued to receive mRNA vaccines (Pfizer and Moderna), and that yesterday’s announcement did not change that approach.

So, since that announcement, AstraZeneca is approved for “routine use” in people aged 60 and over.

The HSE is to decide whether over 70s will continue to receive the Pfizer and Moderna vaccines as the default, or whether there will be a reallocation of vaccines.

Why is the limit of the AstraZeneca jab to over 30s in the UK, but over 60s here in Ireland?

Acting Chief Medical Officer Dr Ronan Glynn stressed that although they are recommending the AstraZeneca vaccine for use over 60s, they could have put the limit at a lower age.

It was due to an abundance of caution that it wasn’t, he said.

He and Dr Lorraine Nolan of the HPRA pointed out that the AstraZeneca vaccine is still effective at stopping a significant proportion of the population from dying of Covid-19.

The reason the advice is changing, they added, is because they are in the “lucky” position of having other effective Covid-19 vaccines to choose from.

Can I choose what vaccine I get?


There is no picking and choosing what vaccine you want, Professor Butler said.

For the age cohort specifically aged above 60, if you get offered an AstraZeneca vaccine, the advice is to accept that vaccine.

Speaking about how people should take what vaccine they’re offered, Dr Ronan Glynn said:

“If someone aged 65 is thinking of taking this vaccine if its offered to them in the coming weeks, versus waiting for the summer when there’s a surplus of other vaccines, I would highly, strongly recommend that they take what they are being offered now.”
“What’s being offered is a very safe, very effective vaccine for their age cohort. The risks of them catching Covid-19… and ending up dying of that disease are far, far, far higher than any potential risk on receipt of one of these vaccines.”

Can I still get the AstraZeneca vaccine if I’m under 60?

From today, all AstraZeneca vaccinations are paused, while the HSE comes up with an operational plan based on the new advice.

Professor Karina Butler said that she can’t speak for the programme on whether it would be “practical”, but said that NIAC’s recommendation is that the AstraZeneca vaccine can be given to those aged under 60 if they are made aware of the risks and an individual assessment is made for that person’s situation.

Why the delay between first and second doses for some people who have had the first AZ dose?

Health officials said that people under the age of 60 and with no conditions should be confident that the vaccine is safe and effective.

The reasoning for the delay between first and second doses being extended from 12 weeks to 16, was to reassure people as much as possible that the vaccine is safe.

Over 800,000 people in the UK have received a second AstraZeneca dose without any evidence of adverse events, Professor Butler said.

Germany and France have also begun to give mRNA vaccines as second doses to people who received their first AstraZeneca dose, and NIAC is monitoring how effective that approach will be, “so we will have more certainty” around that.

Are women under 60 more at risk?

Although initial studies suggested that it was mostly women under the age of 60 who experienced adverse blood clotting after receiving the vaccine, NIAC chair Professor Karina Butler said that this could be because it has been primarily given to healthcare workers, who are women aged under 60.

She noted that in the UK, the 79 rare blood clotting incidents of 30 million AstraZeneca doses administered were among men and women more evenly.

I’ve recently had the AstraZeneca vaccine – what should I do?

Dr Niamh O’Connell outlined the symptoms that people should keep a look out for – but added that these mightn’t necessarily be symptoms of a blood clot either:

The symptoms are: a persistent or severe headache, particularly if it is accompanied by a weakness in your leg or blurred vision. Other symptoms to watch out for are shortness of breath or a pain in your chest or tummy, or ‘pin-prick’ bruising.

Dr Ronan Glynn added that these rare blood clotting events tend to appear between four days and up to two weeks after receiving the AstraZeneca vaccine.

So there is no reason for the vast majority of those who have received AstraZeneca to worry – as they are past this time frame.

For those who are still within that time frame, it’s worth remembering that the incidence of these rare blood clotting events is extremely low: it’s 4-10 cases per 1 million doses administered, one of whom may die.

Have there been cases in Ireland?

The HPRA is still only aware of one suspected case of a rare blood clotting event – but it hasn’t been confirmed as an adverse event as a result of the AstraZeneca vaccine.

Dr Lorraine Nolan confirmed there was still one ‘case of special interest’, but didn’t confirm the details of the person’s condition, due to patient and data privacy reasons.

She did, however, say that as of now, there has been no reported incident of adverse events of low platelets and a clotting event together, which is the rare clotting incident associated with the Covid-19 AstraZeneca vaccine.

Dr Nolan also pointed out that European regulators were the first to become aware of this blood clotting event, and that when they began distributing the vaccine out to the population, they were “open” to the possibility of rare adverse events.

Dr Nolan said that Ireland’s population is so small that a rare event like this may not be spotted unless they looked at data abroad, as was done in this case with European and global data.

Your Voice
Readers Comments
This is YOUR comments community. Stay civil, stay constructive, stay on topic. Please familiarise yourself with our comments policy here before taking part.
Leave a Comment
    Submit a report
    Please help us understand how this comment violates our community guidelines.
    Thank you for the feedback
    Your feedback has been sent to our team for review.

    Leave a commentcancel