At least four people from Germany have died in the last week, Bernhard Ruf, a Leipzig-based infection scientist, told Focus magazine at the weekend.
He said the virus was ‘fit and young', and that those who had been vaccinated against it last year, or had been sick with it and survived, would no longer be protected against infection.
Although the flu season has already begun, Ruf said it was still not too late to get vaccinated. The current seasonal flu vaccine includes an element which protects against the swine flu, he noted.
The Robert Koch Institute – the government's disease control centre – recommends people of any age who have chronic diseases, those over the age of 60, pregnant women and medical personnel should always get the seasonal flu vaccine.
It says that the swine flu virus is dominating the current flu season, accounting for around two thirds of flu infections, and says young adults and children are particularly likely to be seriously ill if infected.
The swine flu virus is no more dangerous than other strains of flu, Christian Meyer of the Bernhard Nocht Institute for Tropical Medicine in Hamburg said earlier this week. But it was here to stay and should be expected every flu season, he told the Frankfurter Rundschau. “Something like that does not simply disappear,” he said.