vaccinations are free at gov. run health centers
but first you must investigate on which s your health center ...it depends on where you live in qatar
then you must register with them - then you have to know which days they do vaccinations ..
then you have to arrive early because nowadays there are too many people there

if you would rather pay for that - there are a lots of private clinics that do vaccinations I guess they charge you 150 -200 rial per vaccinations