There's no evidence that the swine flu vaccine is causing any serious side-effects, U.S. health officials said Wednesday, 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 received 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.

As of Nov. 7, there have been 36 serious adverse reactions to the flu vaccine in Canada.

U.S. 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 U.S. Centers for Disease Control and Prevention.

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

In particular, officials have been watching for reports of a rare paralyzing condition called Guillain-Barré 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.

There have been only 10 Guillain-Barré reports so far in those who got the new swine flu vaccine since early October, and some of those cases still are under investigation, CDC officials said. Officials consider 10 cases a low number.

Guillain-Barré can occur on its own, and normally between 80 and 160 people are diagnosed with the condition each week in the United States, Schuchat said.

The information comes from a voluntary reporting system that patients and doctors can use if they think something went wrong after a vaccination. Of the swine flu reports, 177 were considered serious, including 11 deaths.

There's no evidence those deaths were due to the vaccine, and there was no common underlying medical condition or other pattern seen in those fatalities, CDC officials said.

The CDC has two other systems for looking for vaccine side-effects, and neither of those have turned up Guillain-Barré cases so far, CDC officials said. If problems occur, it's usually within six weeks of vaccination, they said.