Flu Shot Patch Could ‘Obviate' Needle-Based Vaccination Methods
Peptides disrupt skin barrier and promoted responsiveness to an epicutaneous vaccination
An experimental needle-free influenza vaccine patch empowered the immune system of mice without any negative side effects.
According to a new study by the University of Rochester Medical Center (URMC) researchers, this is an important step toward commercializing a technology that could replace needle-based vaccination methods that require healthcare worker administration and biohazard waste removal.
“Scientists have been studying needle-free vaccine approaches for nearly two decades, but none of the technologies have lived up to the hype,” said Benjamin L. Miller, Ph.D., corresponding author and Dean’s Professor of Dermatology at the University of Rochester Medical Center, in a press release on September 16, 2019.
“Our patch overcomes a lot of the challenges faced by microneedle patches for vaccine delivery, the main method that’s been tested over the years, and our efficacy and lack of toxicity make me excited about the prospect of a product that could have huge implications for global health.”
Transporting big molecules like flu vaccine proteins across the skin is difficult to do, as the skin is intended to keep things out of the body, not to let them in.
This URMC study team took lessons learned from the research and treatment of common inflammatory skin diseases to overcome this hurdle and inform their flu vaccine patch strategy.
In patients with eczema or atopic dermatitis, the skin barrier is leaky, allowing pollens, molds and a host of other allergens to enter through the skin and be sensed by the immune system.
These researchers discovered that the expression of a protein called claudin-1 helps maintain barrier strength and lessen the permeability of the skin.
The key would be to disrupt the skin barrier long enough to deliver the virus, but not so long to let unwanted things in.
These researchers designed a patch containing the synthetic peptide and a recombinant flu vaccine and tested 2 scenarios.
In the 1st, they placed the patch on mice to prime the immune system and subsequently administrated an intramuscular flu shot to boost immunity.
In the 2nd they did the opposite, delivering an intramuscular flu shot first to prime the immune system followed by the patch to boost immunity.
In both scenarios, they placed the flu vaccine patch, which looks like a tiny piece of tape, on the backs of mice and left if there for as little as 18 and as long as 36 hours.
The patch effectively opened up the skin barrier, as measured by water loss through the skin.
When the patch was placed first there wasn’t a significant immune response, suggesting that it might not be effective at taking a flu naïve infant who hasn’t received a flu shot or been exposed to the virus to adequate protection.
But, it did initiate a robust immune response (as measured by an increase in antibodies to the flu vaccine virus) when it followed the intramuscular shot, suggesting it could boost preexisting immunity for anyone 6 months or older who has been vaccinated and/or exposed to the virus (mimicking what happens when we get seasonal flu shots year after year).
Importantly, the URMC team saw no physical changes in the skin over the three month period the mice were observed, meaning that the brief barrier disruption didn’t increase the risk of infection.
These researchers concluded saying “When we applied the patch with the peptide the mouse skin became permeable for a short time.”
“But as soon as the patch was removed the skin barrier started to close. We saw significant differences as early as one hour after removal, and by 24 hours the skin was back to normal, which is great news from a safety standpoint.”
The next step in this development process includes additional animal studies to help the team optimize the amount of time the patch must remain on the skin to appropriately boost the immune response.
This URMC team hopes to conduct human trials in the future and believes that if the patch is effective in people it could work for diseases for which there’s already a needle-based vaccine.
The research was funded by a technology development grant from UR Ventures and grants from the National Institutes of Health. In addition to Miller, Beck, and Brewer, Elizabeth Anderson, Radha Pandya, Anna DeBenedetto, Takeshi Yoshida, Tom Hilimire and Luis Martinez-Sobrido contributed to the study. Two of the synthetic peptides developed by the team are patented and two are under a provisional patent.
Several conflicts of interest were disclosed.
The University of Rochester Medical Center is home to approximately 3,000 individuals who conduct research on everything from cancer and heart disease to Parkinson’s, pandemic influenza and autism. To learn more visit University of Rochester Medical Center Research.
Influenza News published by Precision Vaccinations