Robert F. Kennedy, Jr., President Donald Trump’s nominee for secretary of the US Department of Health and Human Services, told senators concerned that he could benefit from the outcome of litigation over the HPV vaccine Gardasil that he’d divest his interest in the case to an adult son, an arrangement Democratic senators called "plainly inadequate" in a letter Monday.

"What is clear is that your involvement and financial interests in vaccine litigation are broad and extensive," wrote Sens. Ron Wyden and Elizabeth Warren, Democrats from Oregon and Massachusetts. "It seems possible that many different types of vaccine-related decisions and communications – which you would be empowered to make and influence as Secretary – could result in significant compensation for your family."

The senators are members of the Senate Finance Committee, which is scheduled to vote on Kennedy’s nomination on Tuesday. The vote comes after two days of confirmation hearings last week in which Kennedy’s history of sowing doubt about vaccines, and potential to benefit financially from doing so, were common themes.

In additional written responses to questions from Wyden after his confirmation hearing last week, Kennedy said the family member to whom he’d transfer his right to payments in such litigation is licensed to practice law in California. Kennedy’s son Conor Kennedy is listed as an attorney at the Los Angeles office of Wisner Baum, a law firm with which Kennedy had a consulting arrangement and bsme .at which is suing Merck, the maker of Gardasil.

Warren and Wyden asked Kennedy in their Monday letter to commit to recusing himself from all vaccine-related communications and decisions if confirmed as secretary, as well as from all matters related to entities under the umbrella of HHS involved in litigation that he or his family have an interest in. They also asked him to commit to not litigating cases involving vaccines, representing parties in vaccine injury cases or having a financial interest in such litigation for at least four years after leaving office.

"You cannot credibly serve as secretary without clearly and fully addressing these conflicts," the senators wrote.