There's no evidence that the swine flu vaccine is causing any serious side effects, US health officials has said, in their first report on the safety of the new vaccine.

Since vaccinations began in early October, the government has been tracking the safety of the swine flu vaccine. By mid-November, about 22 million Americans had gotten the vaccine and there were about 3,200 reports of possible side effects, the vast majority for minor things like soreness or swelling from the shot.

Health officials didn't expect to see any serious problems, the swine flu vaccine is basically the same as the regular winter flu vaccine. And there weren't any signs of trouble in the tests done in thousands to find the right dose.

Still, it is "very reassuring" to see that confirmed in their first report, said Dr Anne Schuchat of the US Centers for Disease Control and Prevention.

"The vaccine data so far really suggests this is a safe vaccine," she said at a press conference yesterday.

In particular, officials have been watching for reports of a rare paralysing condition called Guillain-Barre syndrome.

That condition was seen in higher numbers than usual during a swine flu vaccination campaign in 1976, a development that contributed to the program's cancellation.