Children are the group most affected by influenza this year.
The elderly, particularly those with chronic illness, were most affected last year.
Secretary for Food & Health Dr Ko Wing-man said today the change was due to the difference in flu strains circulating during the two periods.
The main strain this year has been H1N1 while last year it was H3N2, he said, adding this year's flu season started roughly one month later than last year and is so far less serious, according to initial data.
Meanwhile, speaking on online food purchases, he said the Food & Environmental Hygiene Department has introduced a new mechanism for licensing online food sales.
