Vaccinations could be made less painful by treating skin with a vaccine-laden liquid and using ultrasound to push it into the body
Vaccines can be delivered through the skin using ultrasound. This method doesn’t damage the skin and eliminates the need for painful needles. To create a needle-free vaccine, Darcy Dunn-Lawless at the University of Oxford and his colleagues mixed vaccine molecules with tiny, cup-shaped proteins. They then applied liquid mixture to the skin of mice and exposed it to ultrasound – like that used for sonograms – for about a minute and a half.
Since vaginal ultrasound is how they detect a "fetal heartbeat" at 6 weeks (the heart isn't yet formed or pushing any blood, but there's an electronic pulse) at which point abortion is illegal in many states, that might be a good thing.
Although, as ultrasound is also how my overdue fetus was diagnosed with the umbilical cord wrapped 3x around the neck, leading to a quick C-section and healthy baby, I would rather keep the ultrasound machines and lose the lunatics.