Back to the Band-Aid
Perhaps the most remarkable vaccines in early development are those that cross the skin-as injections do-but without a needle. Several groups, including the Iomai Corp. in Washington, D.C., are working on a painless way to tackle this traditional route. Iomai researchers added cholera toxin to diphtheria and tetanus vaccines and rubbed it on the skin of shaved mice. The combination activates Langerhans cells in the skin, some of the mightiest of known immune cells. The mice built up blood antibodies against both diphtheria and tetanus.
The process, known as transcutaneous immunization, “could be particularly useful given the large surface area of the skin and its potent immune cells,” says Gregory Glenn, scientific director of Iomai. Eventually, the immune-stimulating concoction could be incorporated into bandages or patches. Instead of leaving the doctor’s office with a Band-Aid over a vaccination stab wound, a patient could go home wearing the vaccine itself. “It’s an exciting possibility, but we have a tremendous amount to learn,” remarks University of Maryland’s Edelman. For example, researchers don’t even know just how the vaccine crosses the skin. Studies to test the new method in humans are just starting.