An infant's brain tumor has shrunk after the girl's head was kissed by the Pope when he visited the US, according to media reports.

Pope Francis kissed one-year-old Gianna Masciantonio’ during his visit to Philadelphia in September. Last week, her parents said that the tumour had shrunk significantly.

The child's father said the tumour had “basically gone” after many rounds of surgery and chemotherapy. One family friend dubbed the girl’s encounter with the pontiff “the Miracle on Market Street.”