Health chiefs are preparing to deal with around 113,000 cases of swine flu in Northern Ireland in just one week.
GP consultations for flu and flu-like illnesses have decreased with 18 new laboratory-confirmed cases of the condition last week.
But Health Minister Michael McGimpsey said up to 30% of the population may become ill with flu at some point during the pandemic.
He confirmed: "The updated planning assumptions indicate that in Northern Ireland during the peak of the pandemic, approximately 113,000 people could contract swine flu in one week.
"These assumptions do not yet take account of the impact of the vaccination programme, and are not predictions - they are assumptions that allow us, to plan and prepare for the worst, while continuing to hope for the best.
"We now know more about the virus and while in the majority of people it is mild, for some it can be a serious illness. We now know that it isn't a killer but it does kill."
Up to 1% of people who become ill may require hospitalisation and up to 0.1% may die from the virus.
Medics are working to produce a vaccine in time for this autumn's expected surge in the number of cases.
The total number of confirmed cases in Northern Ireland yesterday was 160 but the number of antiviral prescriptions decreased to 384. There have been 56 swine flu hospitalisations and one death.
Chief medical officer Dr Michael McBride said: "The number of contacts made to GPs during this period for flu-like illness has decreased for the fourth week in a row but remains significantly higher compared to this time in previous years, especially for the 15-44 age group.
"Primary care services continue to cope well despite the increased demand on their services."
He urged suspected sufferers to stay at home rather than risk spreading it.