Regardless of what it’s protecting you against, few people would likely say that getting a vaccine injection is an altogether enjoyable vaccine. Fortunately, engineers at the Massachusetts Institute of Technology are coming to the rescue with a new 3D fabrication technique that could allow for multiple doses of a drug or vaccine to be delivered to a patient over an extended period of time — with just one jab needed.

“We figured out a way to make tiny polymer cups, smaller than a grain of sand, that can be filled with any drug, including vaccines,” Ana Jaklenec, a research scientist at MIT’s Koch Institute for Integrative Cancer Research, told Digital Trends. “Once filled, these cups are sealed with a lid made from the same material, and the drug or vaccine is protected inside. Because the microparticles are so small, hundreds can be injected into the arm just like any vaccine. Once in the body, the cups stay closed and open up at a predetermined time, releasing the drug or vaccine. This is exciting because one can fill the different cups with essentially all the vaccines and boosters, and potentially have the 10 to 20 required vaccinations all in one shot.”

These particles are made of a U.S. Food and Drug Administration-approved polymer, which degrades once inside the human body, and allows each one to be “programmed” to degrade at a different time. In experiments involving mice, the researchers showed that the particles injected during one injection could release their contents — with no early leakage — at intervals of 9, 20, and 41 days.

As good as this might sound to those needle-phobic folk fortunate enough to live in a part of the world with readily available health care,  the work’s most exciting application is likely to be in the developing world, where medical resources are more limited. It’s no doubt for this reason that the project attracted the interest of Bill and Melinda Gates, whose foundation funded the work.

“These micro cups could be used to deliver any drug which requires multiple injections over weeks or months,” Jaklenec said. “Single-shot vaccines is one application of this technology which could have significant impact in the developing world, where millions of children remain under-immunized as repeated patient access in some of these areas is challenging.”