The head of the Irish Cancer Society says thousands of people are 'afraid today', 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, CEO of the Irish Cancer Society, told The Hard Shoulder 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."
'It's too early'
She says other measures should have been put in place before the mask mandate was lifted.
"Most Irish people are decent - and we're urging people to show that they care and continue to wear the mask.
"Today's decision from our point of view, and the point of view of many health charities, it's too early.
"There are good developments with new anti-viral medications, which hopefully will mean that if people get them as soon as they're infected that they will be protected against serious illness.
"But we don't have stocks of those yet.
"We don't have access to rapid testing for people who are immuno-compromised like they have in the UK.
"All of that really should have been put in place first before this decision was made".
Put to her that immuno-compromised people can wear masks themselves, Ms Power says this is only half the battle.
"That's only half the picture - they also need other people who are in a crowded space with them to protect them, too.
"Unfortunately while we may be fed up of COVID, it's not fed up of us - and the most vulnerable people in our society need the rest of us to step up and look after them".
And she says while immuno-compromised people simply may not be able to go to 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."