Nasal Spray Flu Vaccine for Kids Proves Highly Effective in Test, U.S. Agency Says

It won't happen this fall or next, but by late 1999 your kids may be able to get effective protection against the flu - and they won't be petrified to get it.

A new type of vaccine administered to young children in the form of a nasal spray was 93% effective in a large scale test, the National Institute of Allergy and Infectious Diseases reports. The agency says that only 1% of the 1,070 kids who received the vaccine got culture- confirmed flu cases, compared with 18% of the 532 kids who received a placebo in the nationwide test. There were no significant side effects reported.

"The initial results from this trial are very exciting," says institute director Dr. Anthony Fauci. "An influenza vaccine given in a nasal spray would be easier to administer and more acceptable than an injection, especially to children." Underlining the vaccine's effectiveness is the fact that there were enough flu cases in the season just past to evaluate the treatment after only one year, instead of two as originally planned.

The vaccine was developed by the institute in association with Aviron, a Mountain View, Calif.-based biopharmaceutical company. The company says that after further tests in the flu season that begins this fall, it plans to seek U.S. Food and Drug Administration approval of the vaccine next summer. If all goes according to plan, Aviron says the vaccine could be available for kids in the fall of 1999.

The institute says the most recent trial took place this past fall with the 1,602 children who ranged in age from 15 months to 6 years. Normally, healthy kids in that age group don't get flu shots - they're usually given to older people who are somewhat more susceptible to the worst effects of influenza.

"We targeted this trial to healthy young children because they experience the highest incidence of influenza disease and often spread the virus to others," says Dr. Robert Belshe, who heads the Center for Vaccine Development at St. Louis University and who chaired the research. "By age 5, most children will have had two or three cases of the flu."

The vaccine used on the kids was a "live-virus" application, meaning that a portion of the active virus was included as part of it. Flu shots given to adults consist of an inactive version of the virus. Researchers say the advantage of the new vaccine is that it grows well in the cooler nasal passages and not in the warmer temperatures of the lower respiratory system. "This allows the vaccine to mimic a natural infection and induce immunity without actually causing disease," says Dr. Brian Murphy of the allergy institute.

Aviron says it is investigating the effectiveness of the vaccine for the treatment of asthma, as well as for use in preventing flu among elderly people.

The vaccine could prove more than just a boon to parents who have to take days off from work to care for a flu-ridden child. "In the face of the next probable serious influenza pandemic, a live- attenuated flu vaccine would provide an effective new tool to combat the disease's spread," says Dr. Dominick Iacuzio, the influenza program officer of the national allergy institute.