The head of the Irish Cancer Society says thousands of people are 'afraid' after the mask mandate is set to be lifted from next Monday.
Masks will not be mandatory in shops, schools and other indoor settings from February 28th.
While people will still be advised to wear them on public transport, they will not be mandatory.
Averil Power says this was too quick.
"Many people with compromised immune systems - and there's over 100,000 people in Ireland who are immuno-compromised - are feeling really worried and afraid today.
"While vaccines provide good protection for most people against serious COVID illness and death - unfortunately that's not the case for immuno-compromised people, like those with blood cancer.
"They're not adequately protected, and they're feeling very worried today about getting on buses and trains and being in retail settings where the person beside them may no longer be wearing a mask."
She says strong guidance, advising people to still wear masks in some settings, is not enough.
"If you're one of those people who is still at really high risk of ending up on a respirator - or indeed still at risk of death from COVID - you don't want to just hope that the person sitting beside you on the bus is going to wear a mask.
"You need to know that they will be."
And she says while immuno-compromised people simply mightn't be able to go to some events, such as the Aviva Stadium, they expect to be protected.
"The reality is blood cancer patients who are currently on active treatment... won't be going to those settings.
"But they don't have a choice about being able to use public transport or go to the shop.
"You'd look for people to feel protected in every setting - but they should at least deserve protection from Government and protection from the rest of society to be able to go about their essential, every day business."