An overview of needle-free injection technology in human vaccines.

With the outbreak of the COVID-19 pandemic, the harmful effects of infectious diseases have gained widespread attention among the public. Vaccination is one of the most effective means of preventing infectious diseases, and the willingness to receive vaccinations is a key factor influencing the success of vaccination programs. Infants and young children, with relatively low immune levels, are a primary target group for preventive vaccinations. However, they often exhibit strong anxiety, resistance, and crying when facing traditional needle-based injections, which highlights the clinical significance of developing needle-free vaccination methods. In recent years, needle-free injection technology has been widely applied to the administration of various medications, but its application in human vaccines remains limited, with only a few commercially available products. This paper provides a review of needle-free injection technology, covering its classification and development history, research progress in vaccine applications, the advantages of needle-free human vaccines, the current status and prospects of market applications, as well as the technical challenges and considerations involved in developing needle-free human vaccines. The review aims to explore the prospects of developing needle-free vaccine formulations for human use.