Pope Francis on Saturday filled the initial positions of a committee against child abuse, which he had announced in December to tackle paedophilia scandals within the Catholic Church.
Francis chose a mixed team of eight prelates and lay experts.
They will have to draw up the statutes of the new panel, setting its tasks and competences, and recruit new members from around the world, the Vatican said.
"Pope Francis has made clear that the church must hold the protection of minors amongst her highest priorities," Vatican spokesperson Father Federico Lombardi said.
Boston Archbishop Sean Patrick O'Malley – one of the eight cardinals who advises the pope on wider church reforms, and who has been at the forefront of efforts to clean up the United States church after cases of child abuse – was the most senior appointee.
Jesuit Fathers Humberto Miguel Yanez of Argentina and Hans Zollner from Germany were also picked. Both are theology professors at the Vatican's Gregorian University, where Zollner organised a historic 2012 seminar on child sexual abuse.
The pope also appointed Irish campaigner Marie Collins, French child psychiatrist Catherine Bonnet, former Polish premier and human rights expert Hanna Suchocka, British baroness and mental health specialist Sheila Collins and Italian canon law professor Claudio Papale.
The Catholic Church's reputation has for decades been tarnished by worldwide scandals about paedophile priests.
In February, UN experts accused it of "consistently" covering up internal cases of child abuse – a charge that the Vatican vehemently denied.
Earlier this month, Francis told Italian daily Corriere della Sera that abuses were "awful", but complained about unfair criticism, insisting that his predecessor, Benedict XVI, had initiated a "very courageous" clean-up process.
"The Catholic Church is perhaps the only public institution that moved with transparency and responsibility. No one else did as much. And yet, the church is the only one being attacked," he said.
The number of priests who have been defrocked after being accused of molesting children has increased dramatically in recent years and the Vatican has stiffened penalties in its legal code for sexual abuse against minors.
But campaigners say such steps do not go far enough. Groups like the Survivors Network of those Abused by Priests want Francis to name and shame bishops who have covered up sex crimes and force priests to report all suspect cases to police. – Sapa-DPA