CompulsoryAccount7746Science - Engineers transform dental floss into needle-free vaccine
"'If [gums between teeth are] highly permeable, could we not use it for vaccination?'
…
engineers added an inactive flu virus … All the mice that were flossed 3 times survived [exposure to real flu], whereas all the unvaccinated mice died. … resembled the [immune] response to vaccines that are sprayed into the nose
…
in humans, … clinical trial testing is needed"
https://archive.is/QNwbm