Sublingual therapy is already used for allergy drugs in children, primarily in Europe.
In this study, mice were given two doses of either live or inactivated flu virus two weeks apart. Both delivery methods were effective in stimulating the immune system.
When later exposed to a severe form of influenza virus, the animals were fully protected.
Delivering vaccine under the tongue also prevented viruses from traveling to the central nervous system, which is a rare but dangerous complication of the nasal spray.
"They basically showed that the vaccine was able to affect change in the immune system and protected against the flu," Reisacher said. "It's an effective way of exposing a vaccine to the immune system. With sublingual delivery, the vaccine is not absorbed that rapidly but it is maintained in the lining of the mouth -- the mucosa -- allowing the antigen to be exposed [to the immune system]."
For more on current flu vaccines, visit the U.S. Centers for Disease Control and Prevention.
SOURCES: William Reisacher, M.D., assistant professor, otolaryngology, Weill Cornell Medical College, and director, allergy, New York Presbyterian Hospital, New York City; Mi-Na Kweon, Ph.D., chief, Mucosal Immunology Section, International Vaccine Institute, Seoul, Korea; Jan. 28-Feb. 1, 2008, Proceedings of the National Academy of Sciences
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