Flu vaccines may soon be delivered by patches coated in microneedles, which dissolve after the vaccine is brought into the skin. The new delivery method has been found to work even better than traditional immunizations at protecting patients.
Osaka University researchers developed the new technique, which uses tiny microneedles made of a material that dissolves in human skin, greatly reducing the risk of infection from the practice. These minuscule needles are composed of hyaluronic acid, which serves to cushion joints in the human body. This material, over time, dissolves in the water naturally found in human skin.
MicroHyala was tested on a group of volunteers, who received doses of a vaccine effective against three strains of influenza. Researchers also immunized a control group using traditional methods. The study showed that those people who received the transcutaneous immunization (TCI) of the vaccine through MicroHyala experienced an equal or greater immune system response than those who took the immunization via a hypodermic needle. None of the people subjected to the new delivery method developed any adverse reactions, suggesting the technique is relatively safe, although the sample of 40 people tested was small, 20 for each delivery system.
This new immunization technique could make delivering vaccines safer, easier and less painful than using hypodermic needles. In addition, these patches can be applied by people without any medical training, potentially increasing the availability of vaccines in third world areas.
"Our novel transcutaneous vaccination using a dissolving microneedle patch is the only application vaccination system that is readily adaptable for widespread practical use. Because the new patch is so easy to use, we believe it will be particularly effective in supporting vaccination in developing countries," said Shinsaku Nakagawa of Osaka University.
The World Health Organization estimates immunizations save the lives of between 2 and 3 million people each day. In addition to influenza, health care professionals are able to protect people from several other dangerous, and often fatal, diseases.
Microneedles attached to patches have been tested in the past. However, these earlier systems were composed of metal or silicon microneedles that often broke off in the skin, potentially causing problems. The points in MicroHyala are harmless, dissolving quickly.
"We have shown that the patch is safe and that it works well. Since it is also painless and very easy for nontrained people to use, we think it could bring about a major change in the way we administer vaccines globally," Nakagawa stated in a press release.
Development of MicroHyala and testing of the efficacy of the new immunization method was profiled in the journal Biomaterials.
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