Some recent papers from both Journal of Virology and Nature shows the feasibility for using centimetre-wide patches with hundreds of thousands half millimetre long micro-needles to deliver vaccines painlessly. I heard about these at a conference a couple of years ago, but it’s only now that they’ve resurfaced with some really promising potential real world use.
The scientists didn’t develop these patches because of needle-phobic patients. Hell no, they couldn’t care less about your ridiculous irrational fears. These patches are more easily manufactured compared to needle, syringe and vaccine; you just print out a sheet, squirt your vaccine on, freeze dry and cut them into squares. On top of that they’re easier to use; just slap it on like a band-aid and then out the door with them.
Also, with these patches, there is absolutely no risk of needlestick injuries and decreases the chance of spreading disease dramatically. The needles do not protrude far enough to get to the blood vessels, where the germs live in high concentrations.
Most importantly, these patches increase the effectiveness of all vaccines. Dendritic cells (DC) are cells that introduce vaccine antigens to the immune system. They capture foreign proteins that are circulating with their squid-like tentacles (or dendrites) and process them so that they can be recognised by immune cells. DC are in greatest concentration in the skin tissue. The micro-needles only puncture half a millimetre into the skin, so they are introduced straight to the DC. Because delivery to the immune system is much more efficient, you need much less vaccine to elicit the same immune response.
Some scientists have used these patches to deliver the flu vaccine to mice and then measured their anti-flu antibodies. Antibody levels were higher in those vaccinated using the patches compared to those vaccinated with a normal metal needle.
This is really exciting technology as it may increase the coverage of vaccinations by making it easier for people to both get it and have a strong antibody response to the vaccine. This would decrease worldwide disease and I guess put us out of a hobby…
Sullivan, S., Koutsonanos, D., del Pilar Martin, M., Lee, J., Zarnitsyn, V., Choi, S., Murthy, N., Compans, R., Skountzou, I., & Prausnitz, M. (2010). Dissolving polymer microneedle patches for influenza vaccination Nature Medicine DOI: 10.1038/nm.2182
Quan, F., Kim, Y., Vunnava, A., Yoo, D., Song, J., Prausnitz, M., Compans, R., & Kang, S. (2010). Intradermal Vaccination with Influenza Virus-Like Particles by Using Microneedles Induces Protection Superior to That with Intramuscular Immunization Journal of Virology, 84 (15), 7760-7769 DOI: 10.1128/JVI.01849-09