A potential game-changer for public health is the mobile vaccine printer developed by MIT researchers that can mass-produce vaccine doses. The patches potentially resolve the difficulties of delivering immunisations to underserved areas because it is not always easy to get immunisations for people who need them. In addition, due to the perishable nature of many vaccinations, delivery to locations without the requisite infrastructure can be challenging.
Stockpiling or shipping vaccines to areas where refrigeration isn’t possible is problematic because most vaccines, including mRNA vaccines, need to be stored at a specific temperature. In addition, they need to be administered by a medical practitioner using a syringe and needle.
The MIT group set out to overcome this roadblock by developing a system for making vaccines on demand. Before the arrival of Covid-19, their primary goal was to create a machine that could mass-produce and rapidly distribute vaccines during a pandemic such as Ebola. Such a device may be transported to a faraway village, a refugee camp, or a military base to expedite the vaccination of large groups of people.
A mobile vaccine printer that can be scaled up to generate hundreds of vaccine doses per day has been developed by MIT researchers as a potential answer to this problem. Researchers claim that this tabletop-sized printer might be used to produce vaccines in any location where they are urgently required.
Ana Jaklenec, a researcher at MIT’s Koch Institute for Integrative Cancer Research, predicted that “we could someday have on-demand vaccine production”. For instance, if there were an Ebola breakout in a particular area, vaccines might be printed out and shipped there to protect the local population.
Patches the size of a thumbnail and packed with hundreds of microneedles were chosen as the new method of vaccine administration to test by the researchers. The patches were printed on a small printer and applied to the skin instead of injections. After being administered to the skin, the vaccine is released through the needle tips. There is a long shelf life for patches when kept at room temperature.
There are polymers in the ink that can be shaped easily and then kept unchanged for weeks or months at room temperature. The researchers found that the optimal combination of stiffness and stability was achieved with a 50/50 mixture of polyvinylpyrrolidone and polyvinyl alcohol, routinely used to create microneedles.
A robotic arm injects ink into microneedle moulds inside the printer, and a vacuum chamber at the bottom of the mould draws the ink down to the bottom, coating the needles. It takes around two days for the moulds to dry after being filled. Researchers believe that future versions might be created to have better capacity than the current prototype, which can make 100 patches in 48 hours.
Such vaccines are now in the research and development stages for various diseases. In mouse experiments, the patches generated an antibody response to Covid-19 RNA vaccinations as robust as that induced by intramuscular injection. Attempting to put RNA vaccines onto microneedle patches was inspired by “concerns about vaccine stability and vaccine access” when Covid-19 was initiated, as MIT postdoc John Daristotle who was involved in the research explained.
When applied to mice, the patches elicited a robust luminous response under all these conditions. However, when stored at room temperature, the brilliant response induced by an intramuscular injection of the RNA encoding the luminescent protein gradually diminished.
Scientists are optimistic that their system may be adapted to manufacture vaccinations against more diseases. Although the vaccines examined in this study were Covid-19 RNA vaccines, the researchers intend to modify the procedure so that it may be used to make other vaccines, such as those based on proteins or inactivated viruses.
