The individual—whose name, age, and sex were not released by local authorities—is the second person to die from the virus amid a growing outbreak along the New Mexico-Texas border, sparking widespread concern among doctors that the federal government’s response is simply not enough to halt the spread of measles.

More and more people are becoming infected in the ongoing measles outbreak in West Texas and New Mexico, where more than 200 people have tested positive for the illness. The disease has killed one unvaccinated child in Texas and is suspected in the death of an unvaccinated adult in New Mexico.

RFK Jr. has cited vitamin A and cod liver oil as effective methods of measles prevention while stopping short of outright suggesting vaccines.