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, the White House said in a 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. The unease led to some lawmakers calling for his resignation.

Miller called Kennedy one of the world's foremost voices, advocates and experts on public health, saying he is working hard to restore the credibility and integrity of CDC, which is recognized globally for its public health measures.

Kennedy does not hold a medical degree and had a background in law before being appointed to lead the Department of Health and Human Services (HHS), which oversees several US health agencies including the CDC.

Recent turmoil included the CDC's permanent firing of 600 employees earlier this month, as reported by a union representing the workers.

The layoffs impacted employees responsible for managing responses to infectious diseases and researching environmental hazards.

Since taking office, Kennedy, a longtime vaccine critic, has enacted various funding cuts and changes to immunization recommendations, drawing ire from public health experts.

Former CDC Chief Medical Officer Dr. Debra Houry expressed serious concerns over the scientific integrity of Kennedy's policies, fearing that they might disrupt the vaccination schedule for children, potentially leading to outbreaks of preventable diseases in the US.

Democratic Senators, including Jon Ossoff and Chuck Schumer, have openly criticized Kennedy, condemning him in harsh terms and calling for his resignation.

Robert F. Kennedy Jr. has publicly committed to improving trust and accountability within the CDC, emphasizing the need for integrity and scientific guidance in decision-making.