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 don’t think there would be any need to dispose of any part of the ultrasound system; perhaps a disposable paper or plastic cover to speed up cleaning between patients. Meanwhile the needles are single use and must be disposed of properly since they are a bio-hazard. Can’t really see how a needle could possibly compete on the waste side of things.
Yeah, maybe he was talking about something else because it’s hard to see what would be worse than used needles.