Low-Temperature Multiple Micro-Dispensing on Microneedles for Accurate Transcutaneous Smallpox Vaccination

Area of Science:

• Vaccinology
• Biomaterials Science
• Immunology

Background:

• Smallpox vaccination traditionally uses scarification with a bifurcated needle, requiring specialized techniques and cold chain management for live vaccinia virus.
• This invasive method presents challenges in administration and vaccine stability.

Purpose of the Study:

• To develop and evaluate a transcutaneous smallpox vaccination method using a microneedle (MN) patch coated with live vaccinia virus.
• To assess the immunogenicity and stability of the vaccine delivered via the MN patch.

Main Methods:

• A low-temperature multiple nanoliter-level dispensing system was used to coat live vaccinia virus in hyaluronic acid onto microneedle tips.
• The vaccine-coated MN patches were applied to mice (BALB/C) to assess immune response.
• Viral titers were measured after storage at -20 °C and 37 °C to evaluate stability.

Main Results:

• Transcutaneous vaccination with the coated MN patch successfully increased neutralizing antibody titers and T cell immune response in mice.
• The live vaccine-coated MN patch demonstrated improved storage stability, maintaining viral titers at -20 °C for 4 weeks and 37 °C for 1 week.
• The dispensing system allowed for precise control of vaccine coating and accurate transdermal delivery.

Conclusions:

• The developed microneedle patch platform offers a simple, effective, and stable method for transcutaneous smallpox vaccination.
• This approach overcomes limitations associated with traditional vaccination methods, including invasiveness and cold chain dependency.