A senior virologist declared on Wednesday a very quiet flu year for Australia as influenza infection rate, including cases of swine flu, has been reduced.

The declaration of Professor William Rawlinson, a visiting fellow at the University of NSW's School of Biotechnology and Biomolecular Sciences, came a day after the World Health Organization announced that the global swine flu pandemic was over.

Rawlinson said there were a small number of flu cases and not much damage was caused even if most of them were swine flu.

In NSW, seven cases of swine flu infection sent victims to hospitals and prompted authorities to remind the public to get vaccinated.

But the swine flu impact is moderate to mild unlike in last year's winter when pregnant women were dying from flu in ICUs.