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.
I think it depends. I went to an ER once that threw me into a wheelchair when the world was spinning post-blood-draw and dropped me off in the hall saying “You’ll be fine!”. That hospital will never get an Ultrasound injector.
When I got my first COVID vax, however, I took up 20 minutes of the time of 2 on-call doctors and a nurse because my passing out often resembles a seizure. And then I took up one of their very few “just in case” beds for close to 90 minutes. Someone else with a problem with needles waiting for a vax had to wait for the bed to open up. They’d have killed to have said ultrasound injector for people like me.