Robert F. Kennedy Jr.'s call for the option to vaccinate against measles, amid an outbreak in Texas, has sparked anger from anti-vax activists, with one saying he is "no different than Fauci."

Health Secretary Robert F. Kennedy Jr., a noted vaccine skeptic, voiced support on Sunday for the measles jab, as an outbreak of the disease spreads.

Known for his anti-vaccination stance, the new US Secretary of Health is facing his first challenge: Curbing the mainly Texas-based measles epidemic which has been encouraged by low vaccination coverage.