Scientists say they now need to examine how serious the symptom is.
NIAC has recommended Novavax's covid 19 vaccine can be used for those aged 18 and older in Ireland.
The Health Minister Stephen Donnelly's confirmed he's accepted this move from the National Immunisation Advisory Commitee.
The update's been given, after the Chief Medical Officer Tony Holohan endorsed these recommendations for the vaccination programme.
'Nuvaxovid', is a spike protein-based jab which can be used for adults who remain unvaccinated or partially vaccinated.
It's expected to be available here next month.
Meanwhile, researchers have found abnormalities in the lungs of Long Covid patients who have breathlessness.
The Explain study shows there's significantly impaired gas transfer into the bloodstream, despite other tests coming back as normal.
Scientists say they now need to examine how serious the symptom is, and the long-term consequences of the condition.