Watch: Key moments from RFK Jr's heated Senate hearing

The article discusses the heated Senate hearing involving Robert F. Kennedy Jr., a prominent figure who has been critical of vaccines. During the hearing, Kennedy Jr. grilled the US health secretary on the government's handling of the COVID-19 pandemic, specifically the high number of deaths and the efficacy of vaccines. The hearing came a week after the head of the Centers for Disease Control and Prevention (CDC) was fired, adding to the tensions. Kennedy Jr. challenged the health secretary's claims about the effectiveness of vaccines, arguing that they have not been adequately tested and that the government has downplayed their potential side effects. The article does not provide a definitive conclusion on the matter, but rather presents the key moments and the opposing viewpoints expressed during the Senate hearing. It highlights the ongoing debate surrounding the government's pandemic response and the role of vaccines in addressing the crisis.