The National Immunisation Advisory Committee (Niac) has recommended limiting the use of the AstraZeneca Covid-19 vaccine to over-60s, due to reports of a number of blood clots in younger patients.
The group has told the Department of Health that those under 60 who have received one dose of the vaccine and suffer with high-risk conditions should receive their second dose after 12 weeks as scheduled.
However, Niac recommended that those who are under 60 without high-risk medical conditions have their second dose extended to 16 weeks to allow for further investigation into the matter.
The HSE has confirmed that all scheduled AstraZeneca vaccine appointments scheduled for Tuesday will be cancelled following the recommendation.
A statement read: “The HSE has this evening written to Hospital Groups and Community Healthcare Organisations to advise that all AstraZeneca Covid-19 Vaccination Clinics planned for tomorrow, Tuesday April 13th, should be cancelled in light of updated guidance received from the National Immunisation Advisory Committee, and the Department of Health, this evening.
“Anybody due to attend an Astra Zeneca clinic is therefore advised not to do so. We will be in contact with patients in due course to rearrange their appointment. We apologise for any inconvenience.
“Following full consideration of the updated guidance, the HSE will advise further in terms of wider implications for the administration of the vaccination programme.”
Commenting on the new advice, Niac chair Professor Karina Butler said: “All the authorised Covid-19 vaccines — Pfizer, Moderna and AstraZeneca and the newly approved Janssen, are highly effective in preventing hospitalisation and severe Covid-19 disease. Vaccination with Vaxzevria Covid-19 AstraZeneca vaccine is highly effective and substantially reduces the risk of severe Covid-19 disease across all age groups.
“Niac realises the need to balance the significant benefits of a national vaccination programme with the very rare risk of these reported events. While this is an extremely rare condition, consideration must be given to the fact that it has a very high risk of death or severe outcome. As the risk/benefits of Vaxzevria Covid-19 AstraZeneca vaccine may vary by age and as alternative Covid-19 vaccines are available Niac has revised the recommendations for use of this vaccine.
“In developing these recommendations, Niac is informed by the available scientific evidence and the risk/benefits of the vaccines. New evidence will be reviewed once available and any further required recommendations will be notified to the Department of Health.
“We strongly encourage everyone to accept the Covid-19 vaccine they are offered. A high uptake of vaccine in every age group is needed if Covid-19 is to be controlled, so that public health restrictions may be safely removed.”
Sources told The Irish Times that up to 14,000 shots that were due to be administered tomorrow will now have to be rescheduled.
AstraZeneca accounts for around 20 per cent of doses due to be delivered to Ireland in the second quarter of the year, with 813,000 due.
The new advice will result in a significant reorganisation of the State's vaccine rollout plan.
Sources said large parts of programme will need to be altered if Niac's advice is implemented, as expected.
One issue that will have to be considered is how vulnerable people in the fourth cohort who are under 60 are inoculated against Covid-19.
The Niac recommendations comes after the European Medicines Agency (EMA) last week warned that extremely rare blood clots were a side effect of the drug that patients should be warned about.
Several EU countries have limited its use to only older people — as the clots have affected younger people — while the UK has confined it to those aged over 30.
Deputy chief medical officer Dr Ronan Glynn said: “As of 7 April, the Health Products Regulatory Authority (HPRA) has been notified of approximately 2,800 reports of suspected side effects associated with Vaxzevria/AstraZeneca, in the context of 204,270 doses administered. The HPRA confirms it has received notice of a case of special interest and is continuing to follow up on this to see if it fits the profile of the very rare blood clots which were the subject of the EMA review. An additional small number of cases describing low platelet counts have been received and follow up is ongoing to rule out the presence of blood clots.
“We will continue to monitor the roll-out of Vaxzevria/AstraZeneca in Ireland and internationally in collaboration with the HPRA and the Niac. The Department of Health, the HSE and the High-Level Taskforce will now work together to ensure that these updated recommendations are incorporated into the ongoing implementation of the vaccination programme."