Inhaled immunity is on the horizon Vaccine: Studies show that a nasal spray can protect children from flu and related ear infections.

November 15, 1998|By Carolyn Poirot | Carolyn Poirot,KNIGHT RIDDER/TRIBUNE Sun Contributing Writer Lesly Borge contributed to this report.

No needle, no tears. A nasal-spray vaccine to protect children against the flu and painful middle-ear infections is showing great promise in a five-year National Institute of Health study being conducted around the country.

In the first three years, the vaccine has been 93 percent effective in preventing flu and 98 percent effective against influenza-associated ear infections in children.

Researchers are trying to determine whether widespread immunization of children 18 months to 18 years old will provide communitywide protection against influenza. The nasal spray being used is FluMist, developed by the Aviron pharmaceutical company, which may hit the consumer market by next fall, pending Food and Drug Administration approval.

At the University of Maryland Medical Center, Dr. James King has conducted studies for a couple of years. The last one tested the efficacy in children and was successful.

In addition to the nasal spray vaccine, a flu pill is being studied at UM. King says a trial will begin as soon as the flu season comes in. Recruitment will begin in December and will target children ages 1 through 12.

"Preschool and school-aged children are at high risk and play an important role in the transmission of flu to family members and the community," says Dr. Pedro Piedra, pediatrician and

associate professor of microbiology and immunology at Baylor College of Medicine in Houston, which is also studying the spray.

"We need universal immunization to reduce the impact in children, which we tend to underestimate. Children have the highest infection rate and one of the highest medically attended illness rates. The hospitalization rate is comparable to that of the elderly. Children just don't die from flu at as high a rate. ...

"For universal immunization, you need a very good vaccine that is accepted by the public," he said. "If children and parents are afraid of it, they are less likely to receive it."

It is estimated that there were 30 million doctor visits last year for acute ear infections. It is the most common illness for which parents take their children to see a pediatrician. By age 3, more than 80 percent of children have had at least one episode of acute otitis media, and nearly 50 percent have had three or more episodes.

The nasal-spray flu vaccine surprised researchers last year by protecting not only against the anticipated flu strains at which it was targeted, but also against A/Sydney, an unanticipated strain not found in the vaccine. By comparison, flu shots provided virtually no protection against A/Sydney.

"We got broader protection than could have been expected," Piedra said. "We need more data, but right now, the studies are very supportive of the notion that nasal spray may provide a greater breadth of protection than the injected vaccine."

The primary difference between the traditional shot and the new spray, other than method of administration, is that the injected vaccine is made from killed viruses and nasal spray is derived from weakened strains of live virus. The spray is easier to produce in large amounts, and easier to administer. Both types of vaccine are grown in eggs, but the injectable vaccine needs one egg per dose, and one egg can produce 1,000 doses of the nasal vaccine.

Pub Date: 11/15/98

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