May 22, 2009

Novel vaccine may stem ear infections

U.S. researchers say they can prevent ear infections in animals with new vaccines rubbed on the skin.

The experimental vaccines were applied in a new way -- a method called transcutaneous vaccination -- which involved placing a droplet of each vaccine onto the ear and rubbing it into the skin

Previous work in our lab showed that after immunization by injection, each of the three vaccine candidates prevented experimental ear infections caused by NTHi, study researcher Laura Novotny of the Research Institute at Nationwide Children's Hospital in Columbus, Ohio, said in a statement.

In the study, four groups of chinchillas were immunized with one of the three vaccine candidates. A fourth group received a placebo. Each vaccine was placed on the ears of chinchillas once a week for three weeks. All animals were exposed to a common cause of bacterial ear infections -- non-typeable Haemophilus influenzae or NTHi -- but only those treated with the placebo were not able to very rapidly reduce or completely eliminate the NTHi from the nose and ear.

Our data are the first to show that transcutaneous immunization is an effective way to prevent experimental ear infections and lays the foundation for an effective, yet simple, inexpensive -- and potentially transformative -- way to deliver vaccines, Novotny said.

The study findings were presented at the American Society for Microbiology in Philadelphia.