A vaccine sprayed up the nose instead of jabbed into the arm with a needle is effective against influenza, a seasonal misery that strikes millions every year and kills about 20,000 of those most vulnerable, a new study shows.
Researchers reported Tuesday that a trial of the nose spray vaccine in 320 children proved it can protect against major strains of the flu as effectively as a vaccine shot."This is a much better way to go," said Dr. James C. King of the University of Maryland Medical Center, the senior researcher in the project. "Kids are terrified of getting shots," and adults don't like them either.
A flu vaccine that is delivered through pain-free nasal spray or drops, King said, "could have important public health effects" by encouraging more people, particularly the needle-averse, to get vaccine protection every year.
Tests at Maryland and five other institutions "found the vaccine delivered good antibody responses, whether it was given through nose drops or the nasal spray," King said at a national meeting of the Pediatric Academic Societies.
"It proved not only to be safe, but much more accepted by children because they did not have to have a flu shot."
The vaccine was tested in children, he said, because that group is the most fearful of injections, often leading parents to avoid flu shots altogether.
"We had parents say they were delighted with the nose spray because it protected their children without needles," said King.
Getting flu vaccine to more children, he said, may benefit everybody. Flu often is spread from child to child at school, and the youngsters take it home to share with the rest of the family.
"If a vaccine keeps children from getting the flu, it may help block transmission in the whole community," King said.
Nose drops or sprays may actually be better at protecting against diseases that attack the respiratory system than are vaccines given as shots in the arm, he said.
King said nose sprays put the vaccine directly on the mucous membrane, the first line of defense against inhaled viruses. He said experiments are under way using nose sprays to deliver vaccines against parainfluenza and respiratory syncytial viruses, both major causes of pneumonia in children.
In the flu study, researchers found that a single dose of nose spray vaccine provided effective protection against two major flu strains and some protection against a third. A new study that uses two doses of the nose spray vaccine is under way, with results expected in the fall.
King said the second dose probably will protect against all three of the flu strains. If the new study shows the vaccine is effective, it could be available for the 1999 flu season.
Dr. Paul M. Mendelman, vice president of Aviron, a Mountain View, Calif., drug company that makes the vaccine, said his firm hopes to seek marketing approval from the Food and Drug Administration late this year or early in 1998.
The research was funded by the National Institute of Allergy and Infectious Diseases.