May 29, 1998

New nose spray vaccine shown to help fight influenza

New nose spray vaccine shown to help fight influenza

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Dr. William Gruber

A new influenza vaccine for children that is sprayed into the nose has been shown to be effective in 98 percent of children who were immunized.

Results of the study ‹ conducted by researchers at Vanderbilt University Medical Center and nine other U.S. medical centers ‹ were published recently in the New England Journal of Medicine.

The study showed that in addition to its effectiveness in treating influenza, the nose spray vaccine also helped curb otitis media, the painful ear infections that often accompany influenza in children.

"These results are a major breakthrough in the battle to immunize children against influenza without the fear and pain of a shot," said Dr. William C. Gruber, associate professor of Pediatrics and Pathology.

This study of the nose-spray vaccine¹s effectiveness in children was made possible by an earlier study by Dr. Kathryn M. Edwards, professor of Pediatrics, Gruber said.

"Dr. Edwards did the largest study in the United States to prove the effectiveness of the nose-spray vaccine in adults. That study is really what paved the way for this one in children," said Gruber.

Influenza epidemics occur yearly and are an important cause of winter-time respiratory illness throughout the world. Infection rates are highest in young children, often exceeding 40 percent. A current vaccine is given by intramuscular injection and is not routinely administered to healthy children.

The direct and indirect costs of influenza and ear infections are tremendous. By the age of five, most children have had influenza three times. In the United States alone, $4.6 billion is spent annually for the treatment of influenza.

"There really needs to be a concerted effort to have children immunized against influenza. This new delivery method will, hopefully, make the entire process of receiving vaccinations easier," said Gruber.

The study's results show that nose drops are an effective way of vaccinating children against influenza. The study enrolled 1,602 children from the ages of 15 months to six years. They were randomized to receive one dose of the spray, placebo or two dosed approximately 60 days apart.

"Of the 1,070 children who received vaccine in the study only one child developed an ear infection and a fever," said Gruber.

The vaccine also caused a 30 percent reduction in the incidence of ear infections (otitis media).

"Ear infections are triggered by having the influenza virus, so it makes sense that if we can stop the virus from infecting children we will reduce the number of ear infections as well," said Gruber.

Vaccines work by stimulating the body's immune system to make antibodies against the infectious agent.

This latest vaccine was designed as a nose spray not only so that it would be easier to give children, but also because there is some evidence that it is more effective to have antibodies from the vaccine placed in the nose, where the infectious virus enters the body in the first place.

This particular vaccine is a live attenuated, cold-adapted trivalent vaccine, which means that it uses a weakened form of the live virus that cannot survive the warmer temperatures in the throat.

Like the vaccine currently being used in adults, the nasal spray version contains two strains of influenza A and one strain of influenza B.