Over the past month, the virus has spread in areas with low vaccination rates, and most of those affected are minors.

A measles outbreak in Texas has grown to 90 cases, mostly among unvaccinated children, state health data published Friday shows.

Some private schools have shut down because of a rapidly escalating measles outbreak in West Texas. Local health departments are overstretched, pausing other important work as they race to limit the spread of this highly contagious virus.