Nasal-Spray Flu Shot Helps
Prevent Infection in Children
By ROBERT LANGRETH
Staff Reporter of THE WALL STREET JOURNAL
Government researchers said a new nasal spray vaccine
for the influenza virus prevented flu in a large test in
children, possibly paving the way for a new class of
easily administered vaccines for large numbers of
patients.
The new vaccine could make it easier to vaccinate many
more children, experts said. Unlike other vaccines, the
new one doesn't require an injection, merely two quick
sprays of the medicine in each nostril. The vast majority
of healthy children don't now get flu shots, in part
because children find shots unpleasant.
OTHER RESOURCE
The National Institute of Health:
nih.gov
And the vaccine, which was developed by the National
Institutes of Health and Aviron, a small biotechnology
company based in Mountain View, Calif., is expected to
cost no more than regular vaccines delivered by
injection.
Researchers involved in the project said that such nasal
vaccines, if approved by the Food and Drug
Administration, could lead to the development of similar
vaccines for other respiratory diseases, including viral
pneumonia and croup.
Aviron expects to apply next year for government
approval to market the vaccine to both children and
adults, and it plans to have the product available for the
1999 winter flu season.
Shares of Aviron jumped $3.75, or 28%, to $17.125 in
Nasdaq trading, after the trial results were announced.
"This is at least as good, if not better" in efficacy than
current flu shots, but much easier to use, said Robert
Belshe, an infectious-disease specialist at St. Louis
University, who helped run the tests. "It could have a
major public health impact."
In particular, researchers said that the nasal vaccine, if it
catches on, could help reduce the flu season's overall
severity by preventing new strains from catching on
among schoolchildren.
"Influenza circulates in schoolchildren, who then bring it
home and pass it on to adults. If you dampen the spread
of the virus in children, you may also slow the spread in
adults" and high-risk groups such as the elderly, said
Dominick Iacuzio, who heads flu research at the
National Institutes of Health.
In the Aviron test, 1,602 children were given either two
doses of the Aviron vaccine or a placebo prior to last
year's flu season. Only 1% of the children who received
the vaccine developed flu, compared with 18% who
received the placebo. Overall, the vaccine was 93%
effective in preventing disease. The Aviron trial didn't
directly compare the new vaccine to flu shots, but
according to government estimates shots are 70% to
90% effective in people under the age of 65.
Besides the new vaccine-delivery method, the Aviron
vaccine differs fundamentally from existing vaccines in
that it uses a weakened form of the living influenza virus
-- rather than a dead virus in current flu shots -- to
generate an immune response. This so-called
"attenuated virus" is safe because it has been altered
only to survive in the relatively cool nasal passages, but
it can't grow in the warmer parts of the lung and throat
that influenza viruses usually infect.
Each year 35 million to 50 million Americans get the flu,
and some 20,000 die from the virus, according to
federal statistics.
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