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
"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