As a measles outbreak sweeps through Texas, officially sickening 124 people, mostly unvaccinated children, and hospitalizing 18, anti-vaccine groups are pushing a familiar and false theory: The highly contagious virus is being caused by the vaccine itself.

A child who was hospitalized with measles in Texas has died from the illness, marking the first death in an outbreak that has infected more than 120 people since late last month. Omar Villafranca spoke to a mom concerned for her 8-month-old baby who's still too young for the MMR vaccine.