The Centers for Disease Control and Prevention has updated its guidelines to recommend that all children from 6 months through 18 years get flu vaccinations, but only 10 percent of parents are aware of the guidelines, the CDC reported.

Each year, more than 20,000 children younger than 5 are hospitalized with the flu in the U.S., according to the CDC. To help spur more vaccinations, the CDC has launched its "Say `Boo!' to the Flu" program to remind parents that the end of October – before flu season peaks -- is a good time to get their children vaccinated. Flu season usually occurs from November through as late as May.

Nurses with Visiting Nurse Associations of America are providing vaccinations at Halloween-themed events nationwide. For more information: http://www.sayboototheflu.com/.

According to a 2008 national survey conducted by market research firm Ipsos, most parents are unaware of how the flu virus can be spread.

Only 10 percent of parents knew that a child can be contagious beginning one day before symptoms develop and for more than seven days after becoming sick, Ipsos found.

Ninety percent of parents did not know that influenza viruses can survive on surfaces such as books, doorknobs, school desks and kitchen counters for up to 48 hours.

The CDC offers tips for preventing the spread of flu after children are vaccinated:

• Sing and Scrub: Make sure kids wash their hands the right way. They should wash frequently with warm water and soap for at least 20 seconds (the time it takes to sing the “Happy Birthday” song twice)

• Disinfect Hot Spots: Kids can touch up to 300 surfaces in 30 minutes. Disinfect the surfaces kids touch most frequently – like doorknobs and faucets – with disinfecting products.

• Do the Elbow Cough: Cough into the inside of elbows, not hands, where they are more likely to spread bacteria and viruses through touch.

• Follow Good Health Guidelines: Eat right, exercise and get plenty of sleep.