Former Centers for Disease Control and Prevention Director Susan Monarez will come before the Senate next week for her first public appearance since she was pushed out of her position, sparking a back-and-forth with Health and Human Services Secretary Robert F. Kennedy Jr. over his vaccine policy agenda.

Monarez will be joined by Deb Houry, former chief medical officer and deputy director for program and science at CDC, who was one of four top CDC officials who resigned in protest after Monarez was ousted. The hearing will be on Sept. 17 at 10 a.m.

The two former officials will testify before the Senate committee on Health, Education, Labor and Pensions (HELP), which is chaired by Republican Sen. Bill Cassidy, a doctor from Louisiana who was one of the key votes to confirm Kennedy but has since become one of his sharpest critics in the Republican Party.

“Children’s health must be the top priority. I thank President Trump and Secretary Kennedy for making radical transparency a priority,” Cassidy said in a statement to announce the hearing.

“To protect children’s health, Americans need to know what has happened and is happening at the CDC. They need to be reassured that their child’s health is given priority. Radical transparency is the only way to do that,” Cassidy said.

Monarez, who HHS publicly announced was “no longer director” on a Wednesday afternoon in late August just four weeks after she’d been confirmed to the position, drew widespread attention when she refused to leave her post, asking President Donald Trump to weigh in and fire her directly if he agreed with his HHS secretary.

She said she was pushed out because she wouldn’t agree to rubber stamp Kennedy’s agenda or fire high-ranking scientists.

The move put a spotlight on Kennedy’s vaccine policy changes, which have ramped up in recent weeks. Kennedy cancelled around $500 million in contracts for mRNA vaccines in early August, changed the recommendations for healthy children and pregnant women to receive COVID-19 vaccinations and, through the FDA, oversaw the narrowing of approval for the updated COVID shots this fall to only people over 65, or younger Americans with underlying conditions.

Later this month, a CDC committee will meet to discuss vaccine recommendations more broadly, including the measles, mumps, rubella, varicella (MMRV) vaccine, and Respiratory Syncytial Virus (RSV). Kennedy has replaced all of the members of the committee with handpicked people, some of whom have expressed criticism of vaccines. Asked by ABC News on Tuesday if he plans to limit access to any of those vaccines, Kennedy said the committee would decide after a “real gold standard scientific review.”

“Parents deserve a CDC they can trust to put children above politics, evidence above ideology and facts above fear,” Monarez wrote in an opinion piece in the Wall Street Journal on Sept. 4. “I was fired for holding that line.”

Kennedy, who testified before the Senate last week in a highly contentious hearing, disputed Monarez’ version of events.

“Did you, in fact, do what Director Monarez has said you did, which is tell her, ‘Just go along with vaccine recommendations, even if you didn’t think such recommendations aligned with scientific evidence?'” Sen. Ron Wyden, D-Ore., asked Kennedy.

“No, I did not,” Kennedy replied.

Kennedy stood by the recent shakeups at CDC, saying they were “absolutely necessary adjustments to restore the agency to its role as the world’s gold standard public health agency with a central mission of protecting Americans from infectious disease.”