Needle-Free Vaccine Injection

Abstract

Millions of people die each year from infectious disease, with a main stumbling block being our limited ability to deliver vaccines to optimal sites in the body. Specifically, effective methods to deliver vaccines into outer skin and mucosal layers--sites with immunological, physical and practical advantages that cannot be targeted via traditional delivery methods--are lacking. This chapter investigates the challenge for physical delivery approaches that are primarily needle-free. We examine the skin's structural and immunogenic properties in the context of the physical cell targeting requirements of the viable epidermis, and we review selected current physical cell targeting technologies engineered to meet these needs: needle and syringe, diffusion patches, liquid jet injectors, and microneedle arrays/patches. We then focus on biolistic particle delivery: we first analyze engineering these systems to meet demanding clinical needs, we then examine the interaction of biolistic devices with the skin, focusing on the mechanical interactions of ballistic impact and cell death, and finally we discuss the current clinical outcomes of one key application of engineered delivery devices--DNA vaccines.

Tetanus vaccination with a dissolving microneedle patch confers protective immune responses in pregnancy

“…Effective cross-talk between innate and adaptive immune responses generates more robust, longer-lasting immune protection [20,21]. We and other investigators have previously reported that skin immunization with metal or dissolving microneedle patches (MNPs) carrying various vaccines (influenza, inactivated poliovirus (IPV), measles, tetanus, HPV, rotavirus, BCG, malaria and RSV) confers immune responses at least non-inferior to conventional immunization as shown by lethal challenge studies, longevity of immune responses and breadth of immunity in a number of small-animal models [21][22][23][24][25][26][27][28][29][30].…”

Needle-free jet injection of hyaluronic acid improves skin remodeling in a mouse model

“…Recently, jet injectors have also been applied in gene and vaccine delivery [10,11]; however, occasional pain and bruising limit their widespread use [12]. For skin rejuvenation, jet injection uses a precise technology to accelerate and laterally disperse skin-enhancing hyaluronic acid (HA) particles via microtrauma using a pneumatic needle-free mechanism.…”

Induction of potent CD8+ T cell responses through the delivery of subunit protein vaccines to skin antigen-presenting cells using densely packed microprojection arrays

“…In this paper, we test the hypothesis that improved delivery methods can augment the efficacy of vaccines by delivering a test-case protein subunit vaccine, ovalbumin (OVA), to the skin's abundant immune cell population using an ultra-high density (>21,000 microprojections/cm 2 ) microprojection array, the Nanopatch (NP), and measure resultant CD8 + T cell responses. Our rationale for this study comes from a growing body of science showing that vaccine immunogenicity can be improved by targeted delivery to the skin ( [25][26][27][28][29][30][31][32]; among others). Specifically, improved immunogenicity (antibody, CD8 + T cell responses, or both) has been generated by targeting virus-based vaccines (live attenuated) to the skin's immune system when compared to standard intramuscular injection [33,34].…”