Hypodermic needless

摘要

Vaccinations are a pain. Any two-year-old with access to reasonable health care will tell you that. But injections are bad for reasons other than the discomfort they cause. If syringes are reused without sterilisation, they can spread disease. The liquid vaccines they require are often temperamental, needing constant refrigeration and thus what is known as a "cold chain" to keep them in tip-top condition as they move from factory to clinic.