In the USA, the CDC recommended against the available needleless flu vaccine option, FluMist nasal spray, during the 2016-17 flu season because it was found to be less effective than the traditional flu shot. "The skin is an immune surveillance organ." said Prausnitz who led the team that designed the microneedles patch for the study. The microneedle patch performed about the same as an injection, regardless of whether the patient had administered it themselves or had a doctor do it.
Adhesive helps the patch grip the skin during the administration of the vaccine, which is encapsulated in the needles and is released as the needle tips dissolve, within minutes.
Public Health England estimated an average 8,000 people die from flu in England each year. Seroconversion percentages from the patches were significantly higher than those in participants who received placebos (P .0001) and similar to those for intramuscular injections (P .01). The patches are relatively cost-effective to produce, could feasibly be self-administered, and will likely enable distribution and storage without the need for cold chain.
Despite seasonal calls nationwide to protect agains the flu, reports indicate only about 40% of adults in the USA get flu shots.
"One of the main goals of developing the microneedle patch technology was to make vaccines accessible to more people". "We do have a lot of people who are typically scared of needles and they were more prone or more excited as being part of this clinical trial so they could try the microneedle instead". Those symptoms only lasted for a few days.
And for needle-phobes (known as trypanophobia) even getting routine immunisations such as a seasonal flu jab can be a stressful experience, so any hope of an alternative "painless" method has to be welcome news. None of the participants had received a flu vaccine during the previous influenza season.
The future of flu vaccines just might come in a tiny, prickly patch. Antibody responses generated by the vaccine, as measured through analysis of blood samples, were similar in the groups vaccinated using patches and those receiving intramuscular injection, and these immune responses were still present after six months. "It has to be a small volume, because you know, the patches are not that big; they can't hold that much", Morse said.
Overall, 70% of the volunteers who got vaccine patches said they'd rather use them again than get a traditional flu shot or an intranasal vaccine.
"This particular patch is very stable at room temperature".
The "more exciting features" of the microneedle patch include its low cost, safety, storage convenience and durability, they said. "Our findings now need confirming in larger trials".
To apply the patch, a person places it on the back of the wrist and presses down with his or her thumb until a click is heard, Prausnitz said.
Professor Robert Booy, of the Westmead Institute of Medical Research, is said the patch is still "three to four years" away from hitting the market, but called it "game changing".