A new injection technique for the influenza vaccine may alleviate concerns of potential influenza vaccine shortages.

The new technique involves the administration of influenza vaccinations in the skin, rather than in the muscle. This could present a solution to the shortage problem, although the application of this technique will probably not be implemented this current flu season.

Concerns about the recent loss of about half the expected vaccine supply were due to a contamination at a Chiron Corporation plant in Great Britain. The Center for Disease Control acknowledged the critical situation and called for state and national public health departments to pursue solutions for the current shortage and examine ways to prevent a vaccine shortage from occurring in future influenza seasons.

Two recent research studies shed light upon how skin injection of the influenza vaccine could reduce the problem of vaccine shortage. The studies examined a total of 338 adults up to 60 years of age. One experiment used 40 percent the normal dosage and the other used only 20 percent the normal dosage.

The studies will appear in the Nov. 25 issue of the New England Journal of Medicine and are also available online at www.nejm.com.

According to the New England Journal of Medicine, the research results illustrated skin injections of a vaccine dosage much lower than the current dose are just as effective, if not more effective, as the typical dose given.

“This is a potential new way to give flu vaccine in the future,” University Health Services Epidemiologist Craig Roberts of the University of Wisconsin said. “Given that the flu vaccine is so difficult to produce, this method, if it proves successful, offers a way to immunize many more people than usual.”

The skin technique is similar to the injection of foreign particles into the skin for allergy testing. Health care providers also used the technique successfully with the rabies vaccine, which has enabled them to administer the vaccinations at a reduced cost, Roberts said.

“[This new method of vaccination] may be [practical] in the future, but not this year,” Roberts said. “The studies would need to be repeated on a larger scale, and then be approved by the FDA and CDC.”

Researchers hypothesized the amount of immunity protection afforded in the current muscular vaccination would provide the same amount of protection in skin vaccination, even when administered in much lower doses.

The scientists based their research on the hypothesis that a greater amount of dendritic cells in the skin than in the muscle evokes a stronger immunological response. Dendritic cells, a type of antigen-presenting cell, are the principle cells that cooperate with white blood cells to initiate an adaptive immune response. These cells acquire the “foreign” influenza virus particles, or antigens, and carry them to lymphoid organs to initiate an immunological response to prepare the body for a later infection by the influenza virus. Injections of the influenza vaccine in the muscle, however, bypass the skin’s immune system and reach a number of tissues that do not have as many antigen-presenting cells.

First-year UW pharmacy student Carrie Capak expressed concern about the new technique, saying the studies are only preliminary and more research should be done before implementing the technique to the general public.

“It sounds like a good idea, but I think much more research should be done. If the method did not work, we would waste the influenza vaccine in a time of great need,” Capak said.