The World Health Organisation has said that only one dose of human swine flu vaccine is needed for protection and that the vaccines are safe.
The news will relieve pressure on health authorities facing limited supplies and uncertainty as to whether one or two shots would be necessary.
The WHO also said that experts had reviewed early results from the monitoring of people who have received pandemic vaccines and said there was no indication of unusual adverse reactions.
It said the adverse events notified were well within those seen with seasonal vaccines.
The Health Service Executive yesterday confirmed that the national vaccination campaign for people at-risk will start on Monday.
It will include people with chronic lung, heart, kidney or liver disease, those with diabetes or neurological conditions and pregnant women.
The HSE says that over 2,100 GPs have agreed to take part in the vaccination programme.
The HSE is also setting up 45 clinics around the country where people can be vaccinated if their local doctor is not providing the service.
It was revealed yesterday that the number of cases of human swine flu in Ireland is continuing to rise.
Over 9,200 people were diagnosed in the past week, according to the latest figures from the Department of Health & Children.
It compares with 7,000 reported cases in the previous week.
Ten people have died in the Republic from the virus to date, 109 people remain in hospital of which 23 are in intensive care.
