(TNND) — Health Secretary Robert F. Kennedy Jr. will visit Congress on Thursday for a hearing on the president's health care agenda, with lawmakers sure to ask tough questions amid the ouster of the Centers for Disease Control and Prevention director and rapidly changing vaccine policies.

Kennedy will testify before the Senate Finance Committee.

“After the mass firings and resignations of respected senior scientists and public servants at CDC over the last 24 hours, it is more imperative than ever that Kennedy answer to the public and their representatives about the chaos, confusion, and harm his actions are inflicting on American families,” Ranking Member Ron Wyden, a Democrat from Oregon, said in a statement ahead of the hearing.

Susan Monarez was ousted as CDC director after less than a month on the job.

Kennedy, a noted vaccine skeptic, remade the expert advisory panel that develops vaccine recommendations for the CDC.

The Food and Drug Administration last week limited its approval for new COVID-19 vaccines from Pfizer, Moderna and Novavax.

All of the vaccines are approved for people 65 and older, and approval for younger people was narrowed to those with underlying health conditions.

And the American Academy of Pediatrics felt it necessary to split with the government vaccine recommendations under Kennedy’s leadership, issuing its own recommendations for kids.

President Donald Trump this week called on drug companies to "justify" the success they claim over COVID-19 vaccines, saying via a social media post that the CDC was being “ripped apart” by the issue.