The skin is a great site to access the systemic circulation of the human body. And that’s exactly where we want the effect of vaccinations to occur. Researchers at King’s College London have showed a way to deliver dried live vaccine to the skin with a microneedle assay and thereby enable immune cells in the skin to set off an immune response. They published their results this week in Proceedings of the National Academy of Sciences.
The microneedle array has microneedles made of sucrose which dissolve once inserted into the skin. Professor Geissmann and his team used this microneedle array with a stable dried version of a live modified adenovirus-based candidate HIV vaccine in sucrose. After observing how the vaccine dissolved in the skin, they also identified the specialized immune cells, a sub-set of specialized dendritic cells, which initiate the immune response for this type of vaccine.
The initiated immune response was equivalent to vaccination using standard needle delivery. Another thing is that the dried vaccine on the microneedle array can be kept at room temperature. It is a great achievement to dry a live vaccine and still maintain the effectiveness after administration, especially through a painless method like a microneedle array.
If this drying method will prove itself in similar results with other vaccines, there won’t be any need for refrigeration of the vaccines anymore. Together with a painless administration on the skin, this can reduce the costs, improve safety and reduce the risks and pain compared to hypodermic needle vaccination.
News release: Injection-free vaccination…
Article abstract in PNAS: Langerin negative dendritic cells promote potent CD8+ T-cell priming by skin delivery of live adenovirus vaccine microneedle arrays
Earlier on Medgadget: Microneedle Patch for Measles Vaccination on Horizon