WEDNESDAY, Feb. 14 (HealthDay News) -- In news that's sure to be met with millions of tiny shouts of glee, researchers report that the nasal spray version of the flu vaccine is much better than the shot at protecting the youngest children against the flu.

In a study that included about 8,000 children under the age of 5, those receiving the live vaccine via nasal spray had 54.9 percent fewer cases of lab-confirmed flu than children receiving the inactive, injected form of the vaccine.

"The nasal spray vaccine was significantly better at protecting children than the standard flu shot," said study author Dr. Robert Belshe, director of the Center for Vaccine Development at Saint Louis University Medical Center, in St. Louis.

Just don't tell your youngster that the flu shot is a thing of the past yet -- the nasal flu vaccine isn't yet FDA-approved for this age group, said Belshe. However, MedImmune Inc. -- the company that makes the vaccine -- has applied for government approval to dispense the vaccine to children under 5.

"It looks like the live attenuated vaccine has promise to improve the prevention of influenza in young children. We'll have to weigh the risks and benefits and we have to see what the FDA has to say, but it's nice that we may have another tool," said the co-author of an accompanying editorial, Dr. Carolyn Bridges, associate director of science in the influenza division of the U.S. Centers for Disease Control and Prevention.

Results of the study, which was partially funded by MedImmune, appear in the Feb. 15 issue of the New England Journal of Medicine.

The study included about 8,000 children -- 8,352 provided complete safety data and 7,852 completed the entire study protocol -- from 249 international sites. Study sites were located in the United States, Europe, Asia and the Middle East.

The children were between 6 and 59 months old, and hadn't had a recent episode of wheezing or been diagnosed with severe asthma. They were randomly assigned to receive either the live attenuated vaccine (FluMist) or the inactivated vaccine by injection.

The live vaccine was significantly more effective -- 54.9 percent fewer cases of flu occurred in those who received the live vaccine vs. the shot.

Belshe said there could be several reasons why the live vaccine is more effective in this young age group. First, when you spray it into the nose, antibodies develop at the location where they're needed most, because the flu virus is transmitted in the air and is often inhaled through the nose. Additionally, the live vaccine seems to offer broader protection against different strains of the flu in children, even in strains not included in the vaccine.

Wheezing occurred more often in children who received the nasal spray vaccine, especially in children under 12 months. For that reason, Belshe said he wouldn't recommend the nasal vaccine for children under one year of age.

Hospitalizations for any cause were also higher in the nasal spray group, but Belshe said the researchers don't know what would cause the increase.

Currently, it's recommended that children with asthma should not receive the nasal spray vaccine, because of the potential increase in wheezing.

"The flu can be a very serious disease in young children and they're the major mechanism for transmitting flu," said Belshe. "The nasal spray vaccine is a significant advance in controlling flu in young children."

While either vaccine is the most effective way of preventing flu, Bridges also recommended practicing frequent, thorough hand washing and covering your mouth when you cough. She also suggested staying home when you're sick and ventilating rooms at home if a family member is ill. Additionally, she said, if you're exposed to someone with flu or have just begun to have flu symptoms in the past day or so, antiviral medication may be helpful.

But, said Bridges, "far and away the best plan is to get vaccinated."

More information

To learn more about the flu vaccine, visit the U.S. Centers for Disease Control and Prevention.