Only a fraction of the people who need flu shots the most are getting them — including just one in five babies and toddlers, say health officials who hope to boost those numbers as a record vaccine supply heads out this fall.

The government sounded the alarm Wednesday, worried that a string of mild flu seasons and the vaccine confusion of recent years are deterring people from this simple lifesaver.

Manufacturers expect to ship more than 130 million doses of flu vaccine in coming months. The message: Anyone who wants to avoid the flu should seek out this ample supply, especially those at high risk of flu complications because of age or underlying illness.

While an early shot is good, don't give up if you can't schedule one in the fall — winter's not too late for protection, stressed Dr. Julie Gerberding, head of the Centers for Disease Control and Prevention.

"We need to rethink the influenza immunization season and encourage vaccination throughout the fall and winter for anyone wishing to be protected," she said.

Flu kills about 36,000 Americans a year, and leads to about 200,000 hospitalizations.

While the flu can be an aching misery for anyone, certain people are at particularly high risk. Flu vaccine is most recommended for anyone over 50 or under 5; people of any age who have asthma, heart disease and other chronic illnesses; pregnant women; and anyone who comes in close contact with high-risk patients, including newborns who can't be vaccinated.

Different strains of influenza circulate every winter. That makes flu vaccination an annual ritual, with a dose brewed specially each year to match the strains experts believe most likely to strike.

But it has been a wobbly ritual in recent years, as vaccine shortages and delays confused patients and frustrated doctors.

Now vaccine supplies appear to be steadily increasing. Yet while the government recommends that more than 200 million people get a flu vaccine each year, new CDC data released Wednesday suggest far too few are heeding that message.

People older than 64 are most likely to get vaccinated — 69 percent during the 2005-2006 flu season, the latest count available. That drops to just over a third of 50- to 64-year-olds, said the new report.

Just 30 percent of younger adults who are at high risk because of underlying illnesses got vaccinated, CDC found.

By 2010, the government wants to have 90 percent of senior citizens and 60 percent of younger adults who are at high risk from flu to be getting vaccinated every winter.

The new numbers suggest that's a goal that may not be met.

Flu vaccine is a little more complicated for young children, because they need two doses a month apart the very first year they're inoculated. Just 21 percent of youngsters ages 6 months to 2 years were fully vaccinated, and just over one in 10 who needed two doses got both, CDC reported.

If a young child missed that necessary second dose last year, health officials are recommending that he or she make it up this year with two shots.