In fiery Senate testimony this week, US Health Secretary Robert Kennedy Jr once again set his sights on the nation's top public health agency, the Centers for Disease Control and Prevention (CDC).

His appearance came days after he suddenly fired the new CDC director, Susan Monarez, provoking a group of senior staff to resign in protest.

At the hearing, when asked for an explanation, Kennedy claimed he had asked Ms. Monarez if she was a trustworthy person and she had replied no, to some disbelief from his opponents in the room.

He then admitted he had once described the CDC as the most corrupt agency in government, and strongly hinted he's not finished with his plans to shake up the organisation.

Kennedy's words have sparked a furious backlash, with many doctors and scientists increasingly concerned that America's public health systems are being dangerously compromised.

It's a conflict that could have a significant impact not just on health policy in the US but across the world. In the past, the CDC has been instrumental in global health, leading responses to crises from famine to HIV and Ebola.

The CDC, founded in 1946, tracks emerging infectious diseases like Covid and tackles chronic conditions such as heart disease and cancer. It operates over 200 specialized laboratories and employs thousands, although its staff has seen cuts in recent years.

Kennedy's controversial record on vaccines is especially worrying to public health experts, as he has accused vaccines of causing harm and hired critics to reassess CDC data. His recent actions have led to shakeups in leadership, with the potential to change critical health policy.

The implications of Kennedy's actions reach far beyond America; decisions made by the CDC affect global health. Experts warn this could undermine years of progress in pandemic preparedness and public health reliability.

As his clashes with the CDC continue, the world will be watching closely to see how this drama unfolds and what it might mean for health policy both locally and globally.