By Chad Terhune (Reuters) -As a measles outbreak spreads across West Texas, Dr. Ana Montanez is fighting an uphill battle to convince some parents that vitamin A - touted by vaccine critics as effective against the highly contagious virus - will not protect their children.

The outbreak is in nine counties in the southern plains. Three of those counties are in the district the speaker represents.

A measles outbreak in West Texas has expanded to over 120 cases across nine counties, marking the largest outbreak in the state in three decades. The virus has also spread to New Mexico and North Texas, with health officials confirming a case in Rockwall ...