ATLANTA -- There's no evidence that the H1N1 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 H1N1 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 H1N1 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-Barre syndrome. That condition was seen in higher numbers than usual during a flu vaccination campaign in 1976, a development that contributed to the program's cancellation.

There have been only 10 Guillain-Barre reports so far in those who got the new H1N1 flu vaccine since early October, and some of those cases still are under investigation, CDC officials said.

Ten is low. Guillain-Barre can occur on its own, and normally between 80 and 160 people are diagnosed with the condition each week in the U.S., 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 H1N1 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-Barre cases so far, CDC officials said. If problems occur, it's usually within six weeks of vaccination, they said.

Since it was first identified in April, H1N1 flu has sickened an estimated 22 million Americans, hospitalized about 98,000 and killed 4,000. It has proved to be similar to seasonal flu but a bigger threat to children and young adults.

Only a few million doses of H1N1 flu vaccine were available at the beginning of the campaign, but about 50 million doses have now been shipped, and the supply continues to increase, Schuchat said.

Health officials are increasingly worried about severe cases of bacterial pneumonia seen in non-elderly adults this fall. The H1N1 flu virus and bacteria can act as a dangerous one-two punch, and information from Denver in October indicates bacterial pneumonia may be occurring at triple the normal rate, Schuchat said.

She urged adults with chronic conditions like asthma, diabetes and heart disease to get a pneumococcal vaccine, which protects against bacterial infection.