Little U.S. flu activity so far, CDC says

(HealthDay)—Flu activity in the United States remains at low levels, federal health officials said Thursday.

"Traditionally flu activity starts to pick up at the end of October, and it normally peaks sometime after the first of the year and starts to wind down by March or April," said Tom Skinner, a spokesman for the U.S. Centers for Disease Control and Prevention.

Each flu season is different, Skinner said, adding, "Sometimes it can arriver earlier, sometimes it can arrive later."

It's too soon to tell what kind of flu season this year's will be, he said. Based on what's known so far, the CDC said the circulating flu strains seem similar to those in this year's vaccine.

Skinner noted, however, that based on limited data it's too early to be sure this year's vaccine is a good match.

"Right now some of viruses we see circulating aren't in the vaccine, but it's a really small sample, so we will have to wait and see what happens when activity picks up," he said.

"Even when activity picks up we can't predict what kind of season we will have in terms of severity," he added. "But we do know we are going to have a flu season and we do know vaccination is the most important thing people can do to protect themselves."

Everyone 6 months and older is urged to get vaccinated, Skinner said. It's expected there will be 135 million doses of vaccine available, he said. "Hopefully, we have enough vaccine for everyone who wants to get vaccinated," he said.

The most common strains of flu detected so far in the United States and around the world are influenza A (H3N2), 2009 influenza A (H1N1) and influenza B viruses, according to the CDC.

Since mid-July more than 300 cases of swine influenza A (H3N2) have been reported. The majority of cases resulted from direct contact with pigs, the CDC said.

The flu report was published in the Oct. 5 issue of the CDC's Morbidity and Mortality Weekly Report.