If the bread has past it's expiration date and the bread smells like vinegar then it likely has gotten bacteria in the bread and should not be eaten.
Some bread can sometimes pick up a normal sourdough-esque bacteria and cause a sour or vinegar smell to it.
I personally would not recommend eating the bread that smells like vinegar because it likely is bad though.
Still if you did happen to eat the bread and the vinegar smelling bread was actually bad then you would likely just get a stomach ache, vomiting etc.
It's unlikely to make you deathly ill but I personally would just throw the bread out if it smells off or smells like vinegar.
Most bread should not have any other smells or vinegar smells.