The HSE is looking at a "no jab - no job" policy in Ireland.
The measure has just been announced in New Zealand, where doctors, nurses and other frontline healthcare workers must be vaccinated against Covid.
HSE chief clinical officer Colm Henry says the issue is being considered.
But he says the vast majority of healthcare staff are already vaccinated.
"This will be a decision for the government and it's something we are considering in the HSE but what I would say is that the overwhelming majority of healthcare workers have embraced the vaccine but have acted as advocates for their patients and their colleagues at work."
The number of people in hospital with Covid-19 has increased to 400 for the first time since the beginning of March.
Admissions to ICU have also increased by 20% in the space of a week, with the latest figures showing 74 are receiving intensive care.
Meanwhile, daily case numbers have spiked in the past few days, following a steady decline.
Dr. Colm Henry added that he believes a number of factors are behind the increases:
"Some of this is a lag effect of the feedthrough from cases to causing harm, to who they are causing harm among breakthrough infections, unvaccinated people. There's still probably somewhere between 40,000 to 50,000 out there over the age of 40 unvaccinated. This question is to how quickly they get it over what time frame"