No one likes to get vaccines, much less the kind that require repeated shots. Children (and pets) often suffer from needing a long series of booster shots at a very early age. What if we could take pain out of the equation? What if we could take the entire series of injections away and replace it with one procedure? That’s exactly what scientists at the University of Minnesota are working on: a vaccine implant that will deliver all vaccines on a time-released basis, no shots required.
The vaccine implant concept is relatively direct: a doctor inserts a small tablet into your arm, a procedure that's probably about as pleasant as it sounds, but at least you just have to do it once. You then get a prescription for several pills, which you take on specific days to activate each dose of the vaccine. Every time you swallow a pill, the implant in your arm releases another dose of the vaccine until you've received the full series of doses. And once you've completed the vaccination sequence, the implant dissolves. Not only would this be easy for children to handle, but pets would also benefit from fewer visits to the vet (which, let’s face it, traumatizes both pet and pet owner alike).
In tests, scientists created a hydrogel capsule that responds to fluoresceins, commonly used as a dye for medical tests (and approved for use in humans). They put HPV (human papillomavirus) inside the capsules and inserted them into mice. The mice were given a pill that contained fluorescein, which activated the capsule to release a small dose of HPV. The results were successful: the mice with the implants gained the same immune response as mice that were given the actual HPV vaccination.
At the moment, the capsule only works for a single dose of a vaccine. Scientists still need to work on multiple doses, as well as being able to specify how much dose is released per activation. Also, the hydrogel needs to last long enough for a full series of vaccinations. However, we could well be on the road to fewer shots, which means fewer screaming children and fewer howling pets. Even if scientists are working on pain-free needles, and they are, in this case, less is definitely more.