The vaccine being discussed in this thread is for one type of bacterial meningitis (meningococcus). There are also vaccines available for the other two most common causes of bacterial meningitis - pneumococcus and HiB.
Viral meningitis can be caused by a wide variety of different viruses, and so there’s no specific vaccine for it.
Can the vaccine be used on babies and children?
I’m just wondering why we don’t have it widely available here, when we have a meingitis (meningococcus mostly I think) problem.
At my lab, we’ll often get a culture from someone who might be carrying gonorrhea in their throat, and since meningitis is a close relative of gonorrhea, meningitis colonies show up on the selective media. Based on this, I’d estimate that around 20-25% of people carry it in their throats.
Unless I swabbed your throat and incubated the sample on Thayer-Martin media, I wouldn’t know if you carry it or not. 
Most sporadic cases of meningococcal meningitis (outside of domatory/army barracks settings) are caused by the group B serotype, and unfortunately we don’t have a vaccine for that serotype. And while the group C meningococcal vaccine can be used on kids, I don’t know how effective it is on infants - it may not induce much immunity in them. I suspect those reasons are why the vaccine isn’t being used much in that population.
The BIG cause of bacterial meningitis in the under-5 set used to be type B Hemophilus influenzae; now that the HiB vaccine is widely used, we rarely see meningitis caused by Hemophilus anymore. I hope the day will come when we’ll be able to say the same thing about meningococcal meningitis, but unfortunately it’s not here yet.