Yep because as per our current theory , zombies need brainzzzz but im pretty sure those people in Vegas are missing out on BRAINZZZ... So yep it will stay in vegas.
Fun Aside : No. The thing is, Life always finds a way(the virus or pathogen or whatever is still LIFE). If it starts at vegas, it will spread because
- Depending on each person the symptoms may start at different time. Which means some infected person could get on a plane,go back to his country and spread the infection.
- The same thing causing the zombie problem could affect someone's pet dog and it might have delayed reactions. The could become a carrier and owner without knowing would take it back to where ever he/she came from.
Unless there is an instantaneous reaction, it would be next to impossible to completely Quarantine and contain this problem as Vegas is a tourist spot and people from different backgrounds with different levels of immunity power will be present at the ground zero.
Some might have early reactions and some might have delayed reactions.Even more annoying would be some people having no reactions but are simply being carriers.
So TD;lr - No the zombie apocalypse wont stay in vegas if it starts in vegas. Even if all travel vessels are suspended, LIFE ALWAYS FINDS A WAY. If its start, give or take 4-5years. All human race as we know it will be wiped out !