Health officials have played down concerns there is insufficient cash available for everyone entitled to the flu vaccination to get the protection they need.
Dr Lorraine Doherty from the Public Health Agency (PHA) said she is unaware of any resource issues which would make it difficult for the trusts to fully deliver the seasonal flu vaccination programme.
Earlier this month the Belfast Telegraph revealed cash-strapped bosses at the Western Health & Social Care Trust have warned it is unlikely they will meet the target for flu vaccination of healthcare staff.
The PHA launched its seasonal flu vaccination programme today - which will offer protection against a number of strains of the virus including swine flu - and Dr Doherty urged anyone in a clinical at-risk group to ensure they get the vaccination.
She said: "We are trying to get across the message that flu is more serious than you think and it is best to get the vaccination."
The PHA is keen to ensure pregnant women and children with special needs are protected. Dr Doherty said there is no evidence to suggest it is dangerous for those in either category to receive the seasonal vaccine.
She continued: "The flu vaccine does not give you the flu.
"It is there for the sole reason to protect at-risk groups."
Meanwhile, the British Heart Foundation urged all heart patients to get the flu jab this year.