A microneedle vaccine printer for thermostable COVID-19 mRNA vaccines

Nat Biotechnol. 2024 Mar;42(3):510-517. doi: 10.1038/s41587-023-01774-z. Epub 2023 Apr 24.

Abstract

Decentralized manufacture of thermostable mRNA vaccines in a microneedle patch (MNP) format could enhance vaccine access in low-resource communities by eliminating the need for a cold chain and trained healthcare personnel. Here we describe an automated process for printing MNP Coronavirus Disease 2019 (COVID-19) mRNA vaccines in a standalone device. The vaccine ink is composed of lipid nanoparticles loaded with mRNA and a dissolvable polymer blend that was optimized for high bioactivity by screening formulations in vitro. We demonstrate that the resulting MNPs are shelf stable for at least 6 months at room temperature when assessed using a model mRNA construct. Vaccine loading efficiency and microneedle dissolution suggest that efficacious, microgram-scale doses of mRNA encapsulated in lipid nanoparticles could be delivered with a single patch. Immunizations in mice using manually produced MNPs with mRNA encoding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor-binding domain stimulate long-term immune responses similar to those of intramuscular administration.

MeSH terms

  • Animals
  • COVID-19 Vaccines / genetics
  • COVID-19* / prevention & control
  • Humans
  • Mice
  • RNA, Messenger / genetics
  • SARS-CoV-2 / genetics
  • Vaccines*
  • mRNA Vaccines

Substances

  • COVID-19 Vaccines
  • mRNA Vaccines
  • RNA, Messenger
  • Vaccines