Jab is easier to say, like many 'informal' words. There's no reason a reporter should be formal about measles jabs that I can see. So long as the information conveyed is correct it's fine by me for reporters to use common or garden tree-climbing words rather than formal, best-dressed long ones.
What "back then" inconvenience would annoy today's youngsters?
Adult offspring harbouring resentments



that was funny!!