Do all Mexicans (born in Mexico) have the tuberculosis vaccine scar on their arm?

My boyfriend, who was born and raised in Mexico City, has a scar on his right arm that looks sort of like a burn scar. It’s from a tuberculosis vaccine that he got when he was an infant. He says that all people who are born in Mexico and who get the vaccine have this scar. I don’t know if I believe him or not he’s been known to play pranks like this ;)

So… does anyone know about this??