Physical methods to overcome tissue barriers in vaccine delivery
Vaccine Insights 2023; 2(10), 363–380
Vaccination represents one of the oldest and most effective public health interventions. Vaccines are routinely administered via systemic injections. Due to the invasive nature of this technique, it introduces several challenges. Vaccine administration without the use of needles would be beneficial. However, vaccine uptake is significantly limited by the presence of tissue barriers. Here, we review physical methods that disrupt these tissue barriers and enable efficient vaccine delivery. Four methods, namely microneedles, needle-free jet injectors, electroporation, and ultrasound. We focus on how these methods compare to needle-based vaccination in preclinical and clinical studies, and discuss their use in mucosal vaccination. In sum, these methods offer an attractive alternative to conventional vaccine delivery strategies; however, much work needs to be done to further improve their efficacy.