Rabies is spread through the saliva of infected animals — usually a bite or scratch, most often from a dog. It is present across much of Asia, Africa and Latin America, and once symptoms appear it is almost always fatal. That sounds alarming, and it is, but the practical point is simpler: it is entirely preventable, and being vaccinated beforehand changes what happens to you afterwards. If you are exposed abroad without prior vaccination, you need urgent treatment including rabies immunoglobulin — which is expensive, in short supply, and unavailable in many of the places people are most likely to be bitten. Vaccinated travellers skip the immunoglobulin entirely and need only two follow-up doses. It buys you time, and it removes the scramble.