Cases of the highly contagious disease are expected to rise and potentially spread to other states where vaccination rates are low.

Texas' measles outbreak is now at 90 cases, the highest yearly case count since 1992. Experts say the number is likely to grow more. Here's why.

There are worries that the outbreak will spread to more states, and doctors have told one very specific group Americans they actually need a measles booster shot. Marissa Sulek reports.