Francis is under fire over his handling of the decades-old worldwide scandal of pedophile priests, including for not immediately renewing the panel's three-year mandate when it expired in December.
The Pontifical Commission for the Protection of Minors will resume work under the leadership of Boston Cardinal Sean O'Malley, a statement said.
It will have 16 members, including nine who are newly appointed.
The panel will continue "assist(ing) local churches throughout the world in their efforts to safeguard all children, young people, and vulnerable adults from harm," O'Malley said.
New members include abuse survivors who asked to remain anonymous, the Vatican said. Other survivors were members of the old commission but resigned, claiming it was ineffective.