Researchers at MIT and the U.S. Department of Agriculture described a microneedle system intended to deliver vaccines to farmed fish, according to a report published Nov. 2, 2026. The paper in ACS Nano presented water-resistant, food-grade microneedles designed to lightly penetrate and remain attached to fish skin before decomposing, with a shellac layer providing a moisture barrier.

The team reported the microneedles could carry a range of cargos, including bacterial and DNA vaccines, with versions lasting longer in water or releasing vaccine faster; release timing of about 15 minutes to 10 or 24 hours was described as a possible design option. The needles preserved half of DNA plasmids' structure after four weeks of dry storage, the researchers reported. Testing in rainbow trout indicated delivery to fish as small as 1 to 2 grams, whereas traditional needle vaccination works well only from about 30 grams, according to USDA researcher Gregory Wiens.

The authors said further work is needed before farm-scale use. The work was supported in part by MIT's Abdul Latif Jameel Water and Food Systems Lab and the USDA.