Some 7.7 million doses of the vaccine against the so-called swine flu virus will be made available across the country starting in the autumn, it has been confirmed.
The Department of Health's chief medical officer Dr Tony Holohan said today the treaments should be available for distribution after the summer.
A spokeswoman for the HSE said the vaccines were currently being manufactured by the pharmaceutical companies.
She said the number of doses was sufficient to vaccinate "every man, woman and child" in the State but that some people would probably need a second dose.
Workers in "essential" areas needed to keep the economy running - such as the electricity sector - would probably be first to receive the vaccination.
Healthcare workers and vulnerable people, such as those with compromised immune systems, would also be prioritised.
The HSE spokeswoman said planning how to vaccinate the entire population would be a huge logistical operation and that it would take place on a phased basis.
Twelve new cases of the A(H1N1) flu were confirmed in the Republic yesterday and five in Northern Ireland, bringing the total across the island above a hundred. A fourth person died in Britain from the virus.