Sharon Osbourne says her son Jack Osbourne is doing "really, really well" in his battle against multiple sclerosis.

The TV presenter insists the 26-year-old star - who learned of his illness in April, just two weeks after his fiancee Lisa Stelly gave birth to their first child, Pearl Clementine - will survive the disease because of his "positive state of mind," and she has thanked everyone who has supported her son through the traumatic time.

"Osbournes survive everything. We really do. Jack is doing really, really well. He has such a positive state of mind. He is really a positive guy, a good guy. His whole life is that he gives back. It makes him feel good and that is just the way he runs his life. He does an awful lot for the program he is under - Alcoholics Anonymous - and he wants to do as much as he can for MS. I have to thank you, everyone, for all their good wishes. It's been amazing for Jack because I really believe that vibes of prayer definitely help," said Sharon, who has survived colon cancer.