Vaccines for some diseases, like cholera, are not given in Australia because of how rare they are. Nonetheless, I don't see the harm in giving a cholera vaccine to every child like we do got Hepatitis B. If there's no harm, why not just give children vaccination against every single disease we can? Just for safety's sake. What if a child happened to get cholera whilst playing in a bin and caused an outbreak?
Is the reason why this is not done just because of cost?
Every public health decision is a cost-benefit decision involving at least two considerations:
Some vaccines, like the measles vaccine, are extremely safe and long-lasting, so it makes sense to give them universally. Others are less effective, less safe, or last for a shorter time, and so it just isn't worth it to give it to people who aren't likely to be exposed to the disease.
In the particular case of the cholera vaccine, it appears that it rapidly decreases in efficacy, even over the course of a single year. Mass inoculation of a population unlikely to encounter cholera before the vaccine becomes ineffective thus is not a particularly good use of resources.
