Despite the potentially severe consequences of illness and even death, only about 40 percent of adults in the United States receive flu shots each year; however, researchers believe a new self-administered, painless vaccine skin patch containing microscopic needles could significantly increase the number of people who get vaccinated.
An early clinical study at Emory University has shown the potential to deliver influenza vaccines using a dissolvable microneedle patch technology that could feasibly lead to cheaper, more accessible, and patient-acceptable vaccination programs worldwide.
The microneedle patch delivery approach developed by Nadine G. Rouphael, M.D., and her team at Emory University and collaborators at Georgia Institute of Technology comprises a pattern of micron-scale solid conical structures made of dissolvable excipients, which are attached to a patch backing. The system delivers vaccine antigens across the stratum corneum directly into the skin epidermis and dermis.
Dissolvable microneedle patches are already used in cosmetic products, and the same concept has been tested in humans for administering drugs such as parathyroid hormones, the Emory researchers point out. However, studies with similar technologies for delivering vaccines have been largely limited to animals.
Dr. Rouphael’s team has now carried out a first-in-man Phase I study to compare the safety and immunogenicity of Fluvirin® influenza vaccination using the dissolvable microneedle patch technology (administered either by a healthcare worker or self-administered after minimal training) with intramuscular injection in 100 healthy adult volunteers. The results showed that the microneedle patches were well tolerated and were strongly preferred by the participants over the intramuscular injections. Vaccine administration using the microneedle patches was also safe, caused only mild, self-limiting skin reactions, and resulted in similar, robust immune responses when compared with intramuscular injection.
Reporting their study, “The Safety, Immunogenicity, and Acceptability of Inactivated Influenza Vaccine Delivered by Microneedle Patch (TIV-MNP 2015): A Randomised, Partly Blinded, Placebo-Controlled, Phase 1 Trial,” in The Lancet, the researchers suggest that dissolvable microneedle patches could simplify influenza vaccination programs worldwide. 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. Microneedle patches also overcome needle phobia issues, which will significantly increase uptake. “These advances could reduce the cost of influenza vaccination and increase patient access to influenza vaccine, thereby increasing vaccination coverage and protection from influenza morbidity and mortality,” Dr. Rouphael’s team wrote.
Once confirmed by larger trials, the use of microneedle patches for influenza vaccination could have major public health implications on vaccination coverage and protection from disease.