Scientists have developed the world’s first mobile printer that can produce thumbnail-sized patches that deliver mRNA Covid vaccines. The device prints two-centimetre-wide patches that contain hundreds of tiny needles that administer a vaccine when pressed against the skin. These “microneedle patches” offer several advantages over traditional jabs in the arm, including that they can be self-administered, are relatively painless, could be more palatable to the vaccine-hesitant, and can be stored at room temperature for long periods of time.
Benefits of Microneedle Patches
The popular mRNA Covid-19 vaccines from Pfizer and Moderna need refrigeration, which has caused distribution complications, particularly in developing countries that have condemned the unequal distribution of doses during the pandemic. The new printer was tested with the Pfizer and Moderna jabs, but the goal of the international team of researchers behind it is for it to be adapted to whatever vaccines are needed. Robert Langer, co-founder of Moderna and one of the study’s authors, said that he hoped the printer could be used for “the next Covid, or whatever crisis occurs.”
Production and Access to Vaccines
Microneedle patch vaccines are already under development for Covid and a range of other diseases, including polio, measles, and rubella. However, producing them is an expensive, laborious process that often involves large machines for centrifugation. To shrink that process down, the researchers used a vacuum chamber to suck the printer “ink” into the bottom of their patch molds so that it reaches the points of the tiny needles. The vaccine ink is made up of lipid nanoparticles containing mRNA vaccine molecules, as well as a polymer similar to sugar water. Once allowed to dry, the patches can be stored at room temperature for at least six months.
The printed patches are currently being tested on primates, which, if successful, would lead to trials on humans. The printer can make 100 patches in 48 hours. But modeling suggested that, with improvements, it could potentially print thousands a day. Antoine Flahault, director of the Institute of Global Health at the University of Geneva, said that production and access to vaccines could be “transformed through such a printer.” However, Darrick Carter, a biochemist and CEO of US biotech firm PAI Life Sciences, was less optimistic. He said that the field of microneedle patches had “suffered for 30 years” because no one had yet been able to scale up manufacturing in a cost-effective way.