Nasal spray vaccine gives kids more protection from flu than shots

Feb 18 2007

In a new study involving thousands of children across the world, a new version of the nasal spray vaccine FluMist has been found to be more effective at preventing influenza than traditional flu shots.

The results of tests in 8,475 preschoolers, aged 6 months to 5 years, conducted during the 2004-2005 flu season with children from the United States, Europe, the Middle East and Asia, have shown that the spray also dramatically reduced the risk of flu-related ear and lower respiratory tract infections.

However the researchers found that for infants age 6 to 12 months, or older children who sometimes wheeze when they breathe, the old-fashioned shots are safer.

Health officials hope the results will encourage parents to consider flu vaccinations for those aged 6 months to 5 years to prevent the spread of the virus.

The traditional flu shot and the nasal spray flu vaccine stimulate different types of immune responses.

The flu shot stimulates antibodies in the blood, the nasal spray vaccine stimulates antibodies both in the bloodstream and in the nose, which is where the flu virus usually enters the body.

The old style shots in the arm or thigh which use killed virus particles, were found to provide less protection to children under 5 than to adults, and may possibly cause more side effects.

The new spray uses live weakened viruses and it was found that while both treatments reduced children's flu rate, 8.6 percent of children getting injections developed flu, while the rate was 3.9 percent for the children given the spray.

Robert Belshe of the Saint Louis University School of Medicine in Missouri and colleagues say children get the flu twice as often as adults and bring the illness home, then pass it on to adults in their household.

Belshe says it is therefore important to vaccinate children against influenza and to identify new and more effective flu vaccine options.

Belshe believes the nasal spray flu vaccine appears to provide a more complete immune response.

Influenza is serious a disease and can be potentially deadly in the elderly and the very young.

More than 30,000 adults die each winter because of influenza and its complications.

The study is the largest ever pediatric study comparing a nasal spray flu vaccine with the traditional flu shot.

The research is published in the New England Journal of Medicine.