The Tanaiste has moved to reassure people over the safety of the AstraZeneca vaccine saying he would personally take it if offered.
The vaccine is now only being given to people over 60 following some rare blood clots in younger people.
Thousands of AstraZeneca vaccine appointments have been cancelled today as a result.
The Tanaiste says he would personally take the AstraZeneca vaccine if offered and has no hesitation in recommending it.
"Speaking s a healthcare professional as well as a politician, I would have no hesitation recommending the AstraZeneca vaccine to people over 60 because the risk of getting this very rare blood clotting disorder, which is probably treatable, is minuscule compared to getting Covid and getting sick or dying from that."
He said they made the right call in limiting the vaccine.
"It is easy to second guess them but if they got it wrong they would have few friends and few supporters if they did.
"I know some people would say they are acting out of an excess of caution but what they would say is they are acting out of an abundance of caution.
"I think on balance that they have got it right."
Sinn Féin's Health Spokesman David Cullinane says the scientific advice has to be followed.
"Obviously what we want is for as many vaccines to be in circulation as possible and for many people to be vaccinated as quickly as we can get people vaccinated.
"But safety also has to come first and that is the responsibility of the NIAC to make those safety recommendations."
People aged between 60-69 will now mainly receive the AstraZeneca vaccine.
There are around 400,000 people in this age cohort.