The White House is defending Health Secretary Robert F. Kennedy Jr. after a chaotic week at the US Centers for Disease Control (CDC) that led to calls for his removal.

On Friday, White House Deputy Chief of Staff Stephen Miller called Kennedy, also known as RFK Jr, a crown jewel of this administration.

Earlier this week, CDC Chief Dr. Susan Monarez was fired because she was not aligned with the president's agenda, according to a White House statement, and was replaced by RFK Jr's deputy Jim O'Neill.

At least three senior CDC leaders have since resigned over frustrations about Kennedy's leadership and vaccine policy, leading some lawmakers to call for his resignation.

Miller called Kennedy one of the world's foremost voices, advocates, and experts on public health and said he is working hard to restore the credibility and integrity of the CDC, which is among the premier public health institutions globally.

Kennedy, who lacks a medical degree and has a legal background, has faced criticism since his appointment, particularly for his funding cuts and changes in how immunizations are recommended and regulated in the US.

Concerns over Kennedy's leadership and the CDC's management surfaced after the agency permanently laid off around 600 employees earlier this month. This included critical staff involved in the response to infectious diseases, sparking further alarm among health experts and lawmakers across both parties.

Critics, including several Democratic senators, have denounced Kennedy's policies as detrimental to public health and have expressed fears over potential disruptions to vaccination schedules that could allow preventable diseases to resurface in the US.

Former CDC Chief Medical Officer Dr. Debra Houry, among those who resigned, voiced concern over the agency's ability to conduct sound scientific research and public health responses amid these leadership upheavals.

Kennedy later reassured CDC employees of his commitment to restoring trust and credibility in the agency, stating that reform could strengthen their efforts rather than diminish them.

The controversy continues to unfold as lawmakers from both parties seek more oversight on the CDC's operations and policies under Kennedy's leadership.