The vaccine may come without a needle

Vaccines are traditionally administered with a needle, but this isn’t the only way. For example, certain vaccines can be delivered orally, as a drop on the tongue, or via a jet-like device. Vaccines that appear particularly suitable to needle-free technology are DNA-based ones, including a COVID-19 vaccine being developed in Australia. Needle-free vaccines are attractive as they cause less pain and stress to people with needle phobias. But they have other benefits. Jet injectors and beyond The earliest needle-free injection systems date back to 1866 and used jet injectors. These hand-held devices used pressure to penetrate the skin and deliver medicine. They became increasingly popular around the middle of the 20th century, and were used to deliver vaccines against typhus, polio and smallpox. A hepatitis B outbreak linked to their use meant they were discontinued in the 1980s. However, research picked up again in the 1990s. Variations included a spring-loaded jet injector (a spring is released...