Vaccine patches on the horizon

A new form of vaccine delivery consisting of hundreds of "microneedles" could allow people to painlessly administer their own vaccinations.

Patches containing micron-scale needles that carry vaccine with them as they dissolve into the skin could simplify immunization programs by eliminating the use of hypodermic needles. As well as being painless, the new patches remove the need for disposal associated with normal needles.

One of the developers of the patch, Mark Prausnitz of the Georgia Tech School of Chemical and Biomolecular Engineering, said: "In this study, we have shown that a dissolving microneedle patch can vaccinate against influenza at least as well, and probably better than, a traditional hypodermic needle."

Despite being only 650 microns in length, the needles are able to penetrate the outer layers of the skin - and provide better immunization that conventional approaches.

"The skin is a particularly attractive site for immunization because it contains an abundance of the types of cells that are important in generating immune responses to vaccines" said Richard Compans, professor of microbiology and immunology at Emory University School of Medicine.

In the study mice were given vaccines for influenza - one group with the patches and the other with standard needles. When exposed to the disease, both groups remained healthy, showing that both forms of vaccine delivery were working. But another study in which the mice were exposed after 3 months showed that those using the patches had a better response to the infection.

As well as being painless, the patches could be a highly effective method for vaccination programmes in epidemics, as Dr Prausnitz explains : "The dissolving microneedle patch could open up many new doors for immunization programs by eliminating the need for trained personnel to carry out the vaccination. This approach could make a significant impact because it could enable self-administration as well as simplify vaccination programs in schools and assisted living facilities."

The study was published online in Nature Medicine.

This article was published on Mon 19 July 2010