Vitalius was an ascetic monk associated with the monastic life of Gaza in Palestine who, in his old age, undertook an unusual labor of mercy in the city of Alexandria. According to his life, he belonged to the monastery of Saint Seridus near Gaza before travelling to Egypt at the age of sixty.
On arriving in Alexandria he devoted himself to the conversion of the city's prostitutes. He hired himself out as a day laborer and used each day's wage to visit one of these women, paying her so that she would pass the night without sin while he kept vigil in prayer. He is said to have learned the names of every prostitute in the city and to have visited them in turn, urging repentance and asking that they keep his purpose secret.
Because he made his visits openly and refused to explain himself, his conduct drew gossip, suspicion, and opposition; nevertheless the accounts hold that every inquiry into his behavior cleared him of wrongdoing. He died about the year 625 in Alexandria after being struck on the head by a man who misunderstood his work, managing to return to his cell before he died. After his repose the women he had reformed came forward to reveal the truth of his labors, and his hidden righteousness was made known.