New flu vaccine skin patch could do away with needles
19 September, 2019
Scientists are hopeful that a new type of skin patch could replace needles as a method of flu vaccination. When they tested the skin patch on mice, it elicited an appropriate immune response without side effects.
A recent Journal of Investigative Dermatology paper gives a full account of the research.
"Scientists have been studying needle free vaccine approaches for nearly 2 decades," says study author Benjamin L. Miller, Ph.D., "but none of the technologies have lived up to the hype."
Miller is a professor of dermatology at the University of Rochester Medical Center, NY. He is also one of the two corresponding authors of the study.
The Centers for Disease Control and Prevention (CDC) estimate that the flu caused 48.8 million illnesses, 959,000 hospitalizations, and 79,400 deaths in the United States during the 2017–2018 season.
That season had an unusually high flu burden that was severe across all age groups.
Eczema inspires a new method of delivery
Prof. Miller and his colleagues believe that the new flu vaccine skin patch solves many of the problems that other developers have faced.
In their study paper, the authors explain how previous attempts to deliver a flu vaccine with skin patches have used techniques such as microneedles and electroporation.
However, while enjoying early success, these methods have proved difficult to "implement on a large scale for mass vaccination strategies."
In contrast to these techniques, the new patch uses a novel approach that came to researchers when they investigated the biology of atopic dermatitis, or eczema.
In people with eczema, the skin barrier that normally prevents toxins and allergens from entering the body stops working properly and becomes permeable, or leaky.
The protein claudin-1 is essential for preventing leakiness of the skin barrier. People with eczema have low levels of claudin-1 compared with those without the skin condition.
In previous work, the researchers had shown that reducing claudin-1 in skin cells of healthy people increased leakiness.
This result made them wonder whether they could use a similar method to get a flu vaccine virus into the body through the skin.
The challenge would be to induce leakiness for a length of time that lets in the vaccine virus but does not allow other materials to enter.