Vaccines for most people in Ireland before Covid-19 meant a few shots from the school nurse against measles or mumps — now we have a front-row seat for the complexities of rolling out four new vaccines around the world, in a pandemic.
On Monday, the National Immunisation Advisory Committee (Niac) indicated the AstraZeneca vaccine should be given only to the over-60s.
Yesterday, the makers of the Johnson & Johnson vaccine paused their EU rollout — both decisions caused by potential links with rare blood clotting.
Both vaccines were seen as so-called game-changers in fighting the virus, so what does this news mean for Ireland?
Over-70s and many healthcare workers are not affected, as they receive either Pfizer-BioNTech or Moderna vaccines. Older people were due to get AstraZeneca but that was switched in early February.
However, vulnerable people in group 4 on the vaccine priority list, and thousands of healthcare workers, now face delays.
AstraZeneca clinics were cancelled around Ireland yesterday while the HSE scrambles to redirect the rollout to match evolving scientific advice with vaccine availability.
At least 14,000 people missed out, and many thousands more may have their appointments rescheduled.
Dr Nuala O’Connor, Covid-19 lead for the Irish College of General Practitioners, told RTÉ it could take “at least a couple of weeks” to reset.
The switch came after the European Medicines Agency was notified of 169 cases of cerebral venous sinus thrombosis and 53 cases of splanchnic vein thrombosis from some 34m AstraZeneca doses.
These typically occurred four to 14 days after the first shot.
New data from the US indicates six similar cases were found from almost 7m of the single-dose Johnson & Johnson vaccine.
This type of blood clotting is so rare that Niac said it is “estimated to occur between four and ten in every 1m people.”
A history of clotting — ordinary blood clots — does not increase the chances of developing these rare clots, according to Dr Niamh O'Connell from the National Coagulation Centre.
It was from “an abundance of caution”, says acting chief medical officer Dr Ronan Glynn, that the decision to switch was taken.
A further 813,000 doses are expected here by June. And with the over-70s already receiving a different vaccine, it could mean limiting them to the 483,000 people between 60 and 69.
It has not yet been announced who would receive the Johnson & Johnson vaccine.
It is important to remember Niac and the EMA are satisfied, based on current evidence, that the risks from Covid-19 far outweighs any risk associated with the vaccines.
Niac chair Prof Karina Butler said: “AstraZeneca is a very good vaccine, we have seen from the Scottish data how it dramatically reduced admissions to hospital.”
- People aged 60-64 are 85 times more likely to die from Covid-19 than to develop any blood clotting — rare or otherwise — after getting vaccinated;
- People aged 55-59 are 48 times more likely to die from Covid-19 than develop a blood clot;
- People aged 20-30 are twice as likely to die from Covid-19 than develop a blood clot.
So under-60s will not receive the AstraZeneca vaccine going forward. Anyone over 60 who received one dose will get their second dose 12 weeks later, as normal.
Anyone under 60 in group 4 — people with cancer, disabilities, various chronic illnesses — will receive their second dose 12 weeks later based on their higher risks from Covid-19.
Anyone under 60 in the general population, mainly healthcare workers, who had the first dose will wait 16 weeks for the second. This allows more time to study emerging evidence.
And anyone who developed unusual blood clots after their first dose should report this and not receive a second.
These are viral vector vaccines based on an adenovirus: “Modified or altered harmless viruses that carry the genetic code needed to make one or more spike protein of the SARS-CoV-2 to train the immune system to respond”, said Dr Edel McNeela.
A lecturer in the Department of Science at Waterford Institute of Technology, she said this was done before to fight ebola.
It can be confusing looking at the different national reactions to the problems. Dr McNeela said this is down to differing Covid-19 local situations.
"You need to look at the hospitalisation rates, the infection rates. You need to look at populations who have or have not been vaccinated, who are the priority populations?
“And you need to look at vaccine available in any particular country.”
The UK, she said, cannot be directly compared to Ireland despite being so close.
The latest British advice is only over-30s will receive AstraZeneca routinely. Prime minister Boris Johnson remains bullish about the country's vaccine rollout and the grand reopening this week included pub gardens, much to Ireland's chagrin.
These are not just European problems. Johnson & Johnson decided suddenly to pause its EU rollout following the concerns raised in the US.
American authorities earlier in the day had said: “We are recommending a pause in the use of this vaccine out of an abundance of caution.”
Australia simply cancelled plans to use Johnson & Johnson’s jab, despite prime minister Scott Morrison conceding this could mean all Australians will not now be vaccinated by December, as planned.
The EMA has already advised unusual blood clots with low blood platelets should be listed as very rare side effects of AstraZeneca, and last week announced a review of the Johnson & Johnson vaccine.
The Irish Health Products Regulatory Authority is part of these reviews. It there is “ongoing dialogue” between Europe and the US on vaccines.
It all brings another word to our pandemic vocabulary: Pharmacovigilance.
“Safety is the priority,” said a spokesman for the Irish Pharmaceutical Healthcare Association.
The downward trends of Covid-19 markers in Ireland — just 50 people in ICU and no new outbreaks reported in nursing homes last week — already reflect the positive impact of vaccines, he said
All vaccines go through rigorous testing in trials and then continue to be monitored when in use. We should probably be prepared for even more changes.