When it comes to flu vaccinations, the conventional "one size fits all" approach for adults is coming under question, according to lead researcher Robert Belshe, M.D., director of the Center for Vaccine Development at Saint Louis University.

"We found that we can give lower doses of vaccine, 40 percent of the full dose, if we gave the vaccine not as a shot into the muscle, but if we gave the shot 'intradermally' between the layers of the skin," Belshe said. "This lower-dose intradermal vaccine worked well in adults 18 to 60 years of age."

Intradermal vaccination is an injection between the layers of the skin using a tiny needle, such as what is used for a tuberculosis skin test. Administration of the vaccine in this way involves injecting a small bleb of vaccine into the skin, much like a mosquito bite or allergy skin test, using a very small needle.

Belshe said the lower-dose intradermal vaccine did not, however, work as well in an older population.

A total of 238 volunteers were enrolled at Saint Louis University and the University of Rochester in the study. This included 130 people between 18-60 and 108 older than 60. Some people received a currently licensed influenza shot in the traditional way full dose, using a shot directly into the muscle. A second group received an investigational vaccine by GlaxoSmithKline Biologicals intradermally and with a dose that was 40 percent of the standard dose.

Belshe said when compared with the full dose of vaccine given as the traditional shot, antibody responses to a lower dose vaccine given under the skin were as vigorous in younger persons but not in people older th
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Contact: Joe Muehlenkamp
muehlenk@slu.edu
314-977-8015
Saint Louis University
3-Nov-2004