Swine flu vaccines are still effective despite reported cases of mutations in the A(H1N1) virus, health experts in Europe and North America have said.

Bruno Lina, director of the national flu virus monitoring centre for southern France, yesterday said the mutation of the virus -- blamed for around 6,750 deaths so far worldwide --came as no surprise.

"It was expected, it was announced, and it will happen again," Lina told AFP, adding: "That does not change anything with regard to treatment and vaccines."

In the United States, Anne Schuchat of the Centres for Disease Control (CDC) said the mutation would have no impact on the effectiveness of the swine flu vaccine or the anti-virals.

The experts' comments came a day after the World Health Organisation announced that a mutation had been found in swine flu virus samples taken following the first two deaths from the pandemic in Norway.

However, the Geneva-based UN agency stressed that the mutation did not appear to cause a more contagious or more dangerous form of A(H1N1).

It also revealed that a similar mutation had been observed in Brazil, China, Japan, Mexico, Ukraine and the United States as early as April.