An infectious diseases specialist at St Vincent's Hospital in Dublin and a professor at UCD said he is encouraged to see the action plans to tackle coronavirus north and south of the border come more into line.
But Dr Paddy Mallon, Professor of Microbial Diseases in the UCD School of Medicine, said he hopes the UK Government hasn't left it too late, otherwise people will die needlessly.
"There is no right or wrong plan but there needs to be a common one," Dr Mallon told the Belfast Telegraph.
"The issue for the island of Ireland is that this virus does not recognise sovereignty. Until the last couple of days there was a real fear that the two different approaches could not sit side-by-side on the island. It's encouraging to see a more consistent approach starting to develop, but every day Northern Ireland waits is a day lost.
"There needs to be social distancing, there needs to be an end to mass gatherings and we're staring to see that. The key in the Republic of Ireland is that the community has bought in to the concept. Northern Ireland needs to buy in to it, too. That simply can't stop when you reach the border. Every day Northern Ireland does not work as a whole to fight this is a day wasted.
"We can't afford to let this virus get a hold on a region. If it does we see the number of cases double within 48-72 hours. If there are 30 cases in Northern Ireland on Tuesday, by Thursday that's 60, by Saturday that's 120. Then the numbers start to become frightening. Korea and China put strict measures in place. Then there has been a two-week period of cases multiplying, but after the two weeks the number of cases starts to slow.
"But what we have to do is make sure there are not too many cases already by the time the measures are implemented.
"Every day of inaction, the virus is winning. The time for sitting by and letting others make decisions for us has passed. If we wait too long and allow the virus to overrun us, people will die needlessly," warned Dr Mallon.
"There's no scaremongering going on. I've been in the game for 20 years. I've got colleagues who have been working in infectious diseases for 40 years. No one has seen anything like this.
"When we look at what's happening within China, Italy, these are countries which have a really good set-up, really good specialists, really good hospitals and despite all of that they're train crashes.
"The worst case scenario is that we're going to get thousands of people dying from this infection, that the healthcare system becomes so overwhelmed that even if we could have saved some of these people, the capacity to save isn't there.
"The message to 21-22-year-olds is look around your family, look around the older people in your family and say to yourself, if I don't get this right I might still be here in six months' time, but a few of them might not be. That's the grim reality.
"For a vaccine, we're looking at 18 months. Our only answer right now is non-pharmaceutical intervention. There is no other solution."