NIAC also issued advice for those who have already received a first dose of the vaccine.
The National Immunisation Advisory Committee (NIAC) has recommended the AstraZeneca Covid-19 vaccine should only be given to people aged 60 and over.
The revised advice to the Department of Health comes after the recent investigation by the European Medicines Agency (EMA) which concluded
last week that unusual blood clots should be listed as a "very rare" side effect of AstraZeneca's Covid-19 vaccine.
A review was undertaken by the EMA after some countries reported blood clots in a small number of people inoculated with the jab.
The EMA said at the time most of the blood clot cases reported have occurred in women under 60 years of age within two weeks of vaccination.
NIAC said in a statement tonight: "These rare events are estimated to occur between four and 10 in every one million people, one of whom may die."
On account of this, NIAC has said the AstraZeneca vaccine is not recommended for those aged under 60 years including those with medical conditions which bring very high or high risk of severe Covid-19 disease.
On top of this, a second dose of AstraZeneca's vaccine should not be given to anyone who developed unusual blood clots with low platelets after the first dose.
Meanwhile, NIAC has issued the following advice for others who have already received a first dose of the AstraZeneca jab.
- Those aged 60 and older should receive their second dose 12 weeks later as scheduled.
- Those aged under 60 years with a very high risk or high-risk medical condition should receive their second dose 12 weeks later as scheduled.
- Those aged under 60 years without a very high risk or high-risk medical condition should have the scheduled interval between doses extended to 16 weeks to allow further assessment of the benefits and risks as more evidence becomes available.
Professor Karina Butler, NIAC chair, said in a statement: “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."
HSE has since confirmed that AstraZeneca Covid-19 vaccination clinics planned for Tuesday, 13 April have been cancelled.
Anybody that was due to attend one of these will be contacted to reschedule their appointment.
It said: "Following full consideration of the updated guidance, the HSE will advise further in terms of the wider implication for the administration of the vaccination programme."
