Papal Nuncio is due at the Knock shrine's annual novena
The Papal Nuncio to Ireland is due to visit the Marian shrine of Knock in County Mayo.
Archbishop Charles John Brown will make the homily at the closing day of the annual Novena.
His predecessor, Archbishop Giuseppe Leanza, was recalled to Rome last year.
It followed a report into the handling of allegations of child sexual abuse made against 19 priests in a County Cork diocese between 1996 and 2000.
The Cloyne report accused the Vatican of being "entirely unhelpful" in dealing with the allegations.
The Commission of Investigation report also said the Vatican's decision to brand a document on child sexual abuse as unofficial allowed individual bishops "the freedom to ignore" strict guidelines on protecting children.
The Irish Prime Minister, Enda Kenny, strongly criticised the Vatican for what he said was an attempt to frustrate the Cloyne inquiry.
In an unprecedented Dail speech, Mr Kenny accused the Vatican of downplaying the rape of children to protect its power and reputation.
He said that the Cloyne Report highlighted the "dysfunction, disconnection, elitism and narcissism that dominate the culture of the Vatican to this day".
The Irish government announced its decision to close its embassy to the Vatican last November.
Archbishop Brown, the Vatican's ambassador to Ireland, has previously pledged to do "everything" in his power to "solidify and strengthen the relations between the Holy See and Ireland".