Texas reported 90 cases this week, while New Mexico reported nine. A majority of the cases have been in a Texas county where vaccination rates have lagged behind the rest of the state.

A total of 159 people have contracted measles in Texas as of Tuesday, according to the state’s health department, marking another increase in an outbreak of the highly contagious virus that was first reported in the state in late January.

Measles is a highly contagious disease. Here's what you should know about how to protect yourself against measles, as well as what's happening in Texas and New Mexico.