It doesn't last as long as the oral vaccine, but it's easier, as long as one doesn't have a needle phobia. I preferred the oral vaccine, because it confers gut immunity, which is what one needs for typhoid. I can see why people mess up while taking it, though. An hour before you eat, no antibiotics (so finish it before starting anti-malarials), not too hot a liquid, keep it in the fridge, a dose every other day (if I'm remembering it all correctly).