The conventional methods of vaccine administration, including intramuscular (IM) injection of mRNA vaccines, have significant limitations for unvaccinated communities in low- and middle-income countries including limited cold-chain-compatible storage, transport infrastructure, and an insufficient number of healthcare personnel. Aimed to address these challenges, Dr. Jaklenec and colleagues developed an automated process for printing thermostable microneedle patches (MNPs) containing COVID-19 mRNA vaccines in a standalone device (see Fig 1) could rapidly produce and deploy vaccines during disease outbreaks–a promising alternative to streamline vaccine delivery and improve access.
The self-applied MNPs dissolve under the skin upon application, eliminating the need for traditional injections. The mobile vaccine printer is small enough to fit on a tabletop and can be deployed to remote areas that lack proper cold storage infrastructure, enabling on-demand vaccine production that can be stored for months at room temperature. The vaccine-containing microneedles are created using an ink loaded with mRNA lipid nanoparticles (LNP) and a dissolvable polymer blend optimized for high bioactivity and optimized to ensure accurate dosing and skin penetration (Fig. 1a, d, h). The dissolvable polymers can be easily molded into the desired shape as the printer's robotic arm injects the ink into microneedle molds, and a vacuum chamber ensures complete filling (Fig. 2). The resulting patches containing mRNA LNPs can remain stable for months. The current prototype can produce 100 patches in 48 hours, with potential for higher capacity in future versions.
Published in Nature Biotechnology, these microneedle patches maintained stability and induced a strong immune response when stored at different temperatures for several months, producing a comparable immune response to that generated by injected RNA vaccines, in mice. The MVP (Microneedle Vaccine Printer) demonstrated successful loading of various biologics, such as protein, DNA, and mRNA-loaded lipid nanoparticles (LNPs), with results that showed comparable immune responses compared to traditional intramuscular injections for the delivery of SARS-CoV-2 mRNA-based vaccines (Fig. 3).
This breakthrough could potentially revolutionize vaccine production and distribution, enabling on-demand vaccines, and expanding access to remote areas. These mobile vaccine printers could be swiftly deployed to combat global outbreaks and reach critical communities, with the potential to improve vaccine accessibility and response to global disease outbreaks.
Find the complete article here: https://www.nature.com/articles/s41587-023-01774-z
