Australia's chief medical officer says there has been a significantly higher number of flu cases than normal in people who have been vaccinated.
Professor Brendan Murphy said this season's vaccine, selected by the World Health Organisation, gave "moderate to good" coverage of the viruses, but it had not been as effective as previous years.
"We have been notified of about 100 deaths from influenza so far this year, but we believe that to be an underestimation," Prof Murphy told reporters in Canberra on Wednesday.
