Date:
01/28/2008 04:38 PM Drop under the tongue could replace needles for flu
vaccination
By RANDOLPH E. SCHMID
AP Science Writer
WASHINGTON (AP) _ Relief may be on the way
for all those youngsters trembling at the thought of another
needle jab. One day the flu vaccine may simply be placed under
the tongue.
Korean researchers say the new vaccine worked
in mice, avoiding not only the painful prick but also the
discomfort some people feel from the inhaled vaccine.
The team led by Dr. Mi-Na Kweon of the International
Vaccine Institute in Seoul reported their findings in Monday's
online edition of Proceedings of the National Academy of Sciences.
Better ways of delivering vaccine have long
been under study, ranging from orally to inhaled, but all
seem to have drawbacks.
Now, Kweon and colleagues say, two doses of
influenza vaccine under the tongue of mice primed the animals'
immune system to fight off what would otherwise have been
a deadly dose of flu.
Next, they are turning their attention to
people, to see if the under-the-tongue vaccine also prompts
a strong immune response.
Placing a couple of drops of liquid under
the tongue gets the vaccine directly to mucus membranes and
prompts a response both in mucus tissues throughout the body
as well as in the immune system itself, the researchers said.
"These studies provide a basis for further
human testing of this alternative form of needle-free vaccination.
Aside from its convenience, sublingual vaccination appears
to disseminate immunity to a broader range of organs than
the classical routes of injecting or ingesting vaccines,"
said Dr. Cecil Czerkinsky, deputy director-general for laboratory
science at the Institute.
"If these findings are replicated in
humans, they could pave the way for the development of a new
generation of vaccines that could be used for mass vaccination
against respiratory infections, including the pandemic avian-human
influenza viruses," he said in a statement.
Several research efforts applying vaccine
to mucus membranes have been tried, seeking to avoid both
the needle sticks that people dislike and the harsh environment
of the digestive system that can damage or destroy a vaccine.
Studies of under-the-tongue of other medicines have also been
done.
Dr. William Schaffner of Vanderbilt University
noted that recent flu studies have involved nasal sprays.
However, he said while he had expected people
to be averse to needles, he was surprised to discover that
"many people are averse to people messing with their
nose ... so there are limitations to nasal spray."
So for researchers looking for another means
of doing this, "just a drop under the tongue at least
will protect mice ... that's a very exciting and promising
line of investigation," said Schaffner, who was not part
of the research team.
And, he added, "if we were faced with
a pandemic, the easier and more acceptable we can make the
distribution of the vaccine the more rapidly we can protect
a proportion of population."
Kweon also said in mouse studies there is
a theoretical possibility of a nasal spray reaching the central
nervous system, which would not happen with the under-the-tongue
vaccine.
The under-the-tongue vaccine worked whether
it was a live or inactivated virus, Kweon reported. And, she
added, it could also be flavored to make it more acceptable.
The research was funded by the governments
of the Republic of Korea, Sweden and Kuwait.
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On the Net:
Proceedings of the National Academy of Sciences:
http://www.pnas.org
International Vaccine Institute: http://www.ivi.int
