FluMist spray is better flu vaccine than traditional shots

A nasal spray influenza vaccine that contains live virus is much more effective than traditional flu shots in protecting young children against this highly contagious disease, a major study conducted by researchers from medical schools in St. Louis, Tennessee, California and Finland, found.

The study comparing the two major types of flu vaccine for young children discovered that children from 6 months to 5 years old had 55 percent fewer cases of flu when they were protected by the nasal spray vaccine, called FluMist, rather than shots.

In their study, which published in Wednesday’s issue of The New England Journal of Medicine, the research team led by Dr. Robert Belshe at St. Louis University involved 8,475 children, 6 months to 59 months of age, at 249 sites across the United States, Europe, Asia and the Middle East.

Under the trial, children were randomly assigned to receive either FluMist or the flu shot. Half of the study subjects got active doses of the spray containing weakened, live versions of the viruses found in the shot along with placebo shots. The other half took real shots, which contains three strains of killed flu viruses, along with a placebo spray.

The research team then monitored the study participants for influenza- like symptoms throughout the 2004-05 flu seasons, and examined the nasal swab cultures of those who reported flu-like illness.

After observing the data, researchers found that of the 491 children infected during the ensuing flu season that runs from December through April, 338 had been given flu shots and 153 were treated with nasal spray vaccine FluMist, which translates to about 55 percent fewer cases of culture-confirmed influenza.

The spray was specifically effective at preventing the widely known of the three strains of flu that cause illness each year, slashing cases of the H3N2 strain of flu virus by 79 percent. The nasal spray vaccine FluMist, manufactured by MedImmune that funded the recent study, also dramatically reduced the risk of flu-related ear and lower respiratory tract infections.

"Our primary objective in the study was to determine how FluMist would perform against the flu shot in young children, and to assess the comparative safety outcomes to help us determine for whom FluMist might be most beneficial in the pediatric population," said Edward M. Connor, M.D., MedImmune's executive vice president and chief medical officer. "A careful evaluation of the benefits and risks associated with FluMist in this study demonstrated that FluMist was highly favorable for the nearly 80 percent of the children 12 to 59 months of age who did not have a history of wheezing or asthma."

FluMist spray vaccine, which does not need to be kept frozen, only refrigerated, is not yet licensed by the Food and Drug Administration (FDA) for children under 5, but the fresh study results could lead to major changes in the way they are protected.

U.S. regulators approved nasal spray vaccine last month for healthy children and adults age 5 to 49, but not yet approved it for younger children. Belshe and the manufacturer of the FluMist, Medimmune expect they will get US health agency’s approval for younger children soon, possibly in time for the beginning of the next influenza season.

The Centers for Disease Control and Prevention recommends flu vaccination for those aged 6 months to 5 years to prevent the spread of the virus.