Finns' protection against the swine flu virus has weakened compared to the population's immunity last year, according to Thedi Ziegler of the THL.
During the previous flu season Finland and the rest of Europe enjoyed good protection from swine flu. But this immunity may now have weakened because of people who didn't get the vaccine against the bug.
“Now the virus has the opportunity to find new hosts,” he explains.
This season is seeing two influenza A and one B strain. Ziegler predicts that the H3N2 flu virus, which spread across Finland last year, will be the main culprit this winter. The other A strain, swine flu (H1N1), will likely be less prevalent.