The defined dogma of the Immaculate Conception regards original sin only, saying that Mary was preserved from any stain (in Latin, macula or labes, the second of these two synonymous words being the one used in the formal definition). The proclaimed Roman Catholic dogma states "that the most Blessed Virgin Mary, in the first instance of her conception, by a singular grace and privilege granted by Almighty God, in view of the merits of Jesus Christ, the Saviour of the human race, was preserved free from all stain of original sin." Therefore, being always free from original sin, the doctrine teaches that from her conception Mary received the sanctifying grace that would normally come with baptism after birth.
Who was believed to have prevented this from occurring to Mary ?
privilege granted by Almighty God, in view of the merits of Jesus Christ, the Saviour of the human race, was preserved free from all stain