Simon Harris suggested the vaccine pass may remain in place if the reopening goes ahead.
Leo Varadkar has said there would be "no question" about the proposed Friday, 22 October reopening if everyone in the country was vaccinated.
Speaking in the Dáil on Thursday, Varadkar said that no decisions had been made yet and that Cabinet would be meeting to discuss options on Monday or Tuesday after data from the National Public Health Emergency Team (NPHET) is made available.
"It is a personal choice, but the truth is that, if everyone in Ireland was fully vaccinated, we would probably have approximately 25 people in ICU and 200 in hospital overall today, and there would be no question about easing restrictions on 22 October," he said.
"It is a personal choice, but it has an impact on other people."
Cases in the country have been rising over recent days, leading to concerns about the reopening date with 2,066
new cases reported on Wednesday and a further 1,627 cases on Thursday.
It comes as
Dr Ronan Glynn confirmed that "two out of every three people in intensive care" are unvaccinated against Covid-19.
On Thursday evening, Dr Glynn noted that there is now an average of 50 people being admitted to hospital per day – up from 35 per day at the end of September.
Elsewhere, Simon Harris suggested the vaccine pass may remain in place if the reopening is able to go ahead.
Speaking to reporters at Government buildings on Thursday afternoon, he said that keeping the Digital Covid Certificate in place domestically may "help" with the reopening.
"We are not in this binary position of do we open or not to open," said Harris.
"We have learned a lot about the virus and learned a lot about how to keep us safe. We have a huge amount of our people vaccinated," he said.
Harris continued:
"We should be asking more nuanced questions of each other. How can you open and keep it safely open?"
