Researchers in the Jaklenec and Langer lab are working to deliver multiple vaccine doses in one injection, eliminating the need for repeat clinic visits for boosters, which is especially beneficial in developing countries where many do not receive complete vaccinations. Shown is an injectable and implantable needle made of fully dissolvable materials, designed to deliver two doses of mRNA vaccine at programmed intervals. The first dose is loaded at the needle tip and second is encapsulated in a slow degrading polymer capsule programmed to release its cargo at certain time points. Inspecting the prototypes with a microscope and reviewing images like these help the researchers confirm that different materials successfully ended up at their intended locations.