Kennedy Jr. is revising his ethics agreement to divest his interest in litigation against an HPV vaccine maker and directing the stake to his adult son, The New York Times reported Friday, citing a written response to questions from senators who are weighing his confirmation as Health and Human Services secretary.

Robert F. Kennedy Jr.’s nomination to be the nation’s top health official is uncertain after a key Republican joined Democrats to raise persistent concerns over the nominee’s deep skepticism of routine childhood vaccinations that prevent deadly diseases.