Vaccination in the form of a patch
A futuristic vaccination method would do away with needles and increase ease of use
After reading this article, you will be able to:
- Explain how a dissolvable influenza patch works
- List the potential benefits of distributing vaccines in the form of a needleless patch
- Analyze why the patch form has indicated an improved immune response compared to traditional methods
Imagine if you only had to walk to your mailbox or your local supermarket in order to be vaccinated for influenza. And you could do it all yourself—no lines, no appointments, no doctors, and perhaps most importantly, no needles.
A new study published in the July 18 issue of Nature Medicine indicates this scenario is a real possibility in years to come. This method of self-administered vaccines (particularly influenza vaccines) directly enters the skin in the form of a patch—smaller than a penny—consisting of many microneedles that dissolve into the skin within minutes.
Researchers tested the prototype on mice and found that this method of vaccination generated immune responses “that provided complete protection against lethal challenge” of influenza. Results suggested that influenza vaccines in this form could provide a simpler and safer method, improve resistance and immune response, and could change the way people view flu shots.
Creating a method of vaccination that is easier for the general public to access and use has been the main focus of this project, dating back to 2004, says Ioanna Skountzou, MD, PhD, assistant professor in the Department of Microbiology and Immunology at Emory University School of Medicine and Influenza Pathogenesis and Immunology Research Center in Atlanta.
“One of the things we wanted to do was have a needle-free vaccination that was distinguished from the conventional method of needles,” Skountzou says. “It’s much easier by far because you can self-administer the patch, and it doesn’t need any specific training. So ease of application was very important.”
A history of microneedles
The project began in 2004 when Mark Prausnitz, PhD, a professor in the Georgia Tech School of Chemical and Biomolecular Engineering in Atlanta, began developing the microneedle patch that was made out of stainless steel and consisted of hundreds of tiny needles.
Emory University collaborated with Georgia Tech to explore ways in which the patch could be used for immunization, particularly with the influenza vaccine.
Researchers began by coating the steel microneedles with the influenza vaccine, Skountzou says, and discovered that this method of administration was at least as effective as conventional methods.
“So we decided to take it one step further and try doing the experiment again with the whole inactivated virus with dissolving microneedles,” she says.
Skountzou has not seen any drawbacks in the animal population, although they intend to test the product on ferrets before moving on to humans. They have done some studies on humans with the steel microneedles, and the majority of the participants did not feel any pain.
“In the animal model, we don’t see any irritation or inflammation and everything seems to be very safe,” she says.
Improved immune response
Going into the study, the question was how vaccination through the skin—rather than intramuscularly or intranasaly—would elicit a response in the lungs and protect the recipient from influenza.
Despite the fact that none of the researchers expected vaccination through the skin would affect the lungs, the immune response seems to be better than even traditional methods.
“The skin is an immunological organ, and everybody has known that for more than 100 years,” Skountzou says. “It harbors all kinds of innate cell populations that are accessory cells, but they are recognizing any foreign objects which they take to specialized cells to process further, and then we have corresponding immune responses. The corresponding immunization is actually producing more specific results.”
Further, immunization through the dissolvable patch indicates that immune responses are actually stronger and last longer than traditional methods.
“What hasn’t gotten that much attention is that what we have seen from our data is that we have much better and more prolonged memory responses, and the memory is about immunological memory, which is very, very important,” Skountzou says. “You notice that, for example, with seasonal vaccines, there are circulating strains. Every year the population needs to be vaccinated to boost their response. With the microneedle patches we found that these responses are stronger and longer-lived than the conventional vaccination.”
Increasing ease of use
The most obvious benefit to a dissolvable patch is ease of use, especially during a pandemic, which could require mass vaccination. Rather than long lines at the pharmacy, clinic, or hospital, Skountzou envisions mailing the patch to people for self-administration.
“When you have a pandemic where you have to have a rapid distribution, this is the easiest way to go,” Skountzou says. “Just put the patch on your skin for one to five minutes and leave it there, and then you’ll be vaccinated.”
On a global level, the patch could be easily distributed to countries that have little access to healthcare.
“You can send them by truck and give them to the population, and everybody knows how to put them on their skin, and that’s the beauty of it,” Skountzou says.
This alternative type of immunization could also assist healthcare facilities with employee vaccination rates. An easy-to-use method that doesn’t involve needles may give some healthcare workers an option they feel more comfortable with, says Bruce Cunha, RN, MS, COHN-S, manager of employee health and safety at the Marshfield (WI) Clinic.
Cunha says more employees at his facility have been requesting the nasal spray, especially when that was all they had during last year’s pandemic.
“If there was a patch that we could offer, I know it would assist a number of employees who report a fear of needles,” he says.
When is the patch available?
Ultimately, the big question is when would an influenza vaccine be available in the form of a dissolvable patch?
Although testing still needs to be done—first on ferrets and then on humans—it’s expected to hit the market within the next five years, says Ioanna Skountzou, MD, PhD, assistant professor in the Department of Microbiology and Immunology at Emory University School of Medicine and Influenza Pathogenesis and Immunology Research Center in Atlanta.
“This is not just about doing research for the sake of doing research,” she says. “We want to come up with a product that can be readily available as soon as possible for the population.”
Skountzou also envisions this product being used across multiple platforms, for multiple vaccines outside of the flu shot.
For example, diabetics that need to give themselves insulin injections every day may be able to use this patch as a less painful and safer alternative.
“I know that this has been tried with different vaccines, different drugs, and different viruses, so the perspective in general will change away from needles and towards vaccinations,” Skountzou says.