“This is a message on behalf of Great Ormond Street Hospital,” he said. "I want to thank everybody who has donated to their latest campaign and has given money to keep this great hospital and the great work it does going.
“I also want to congratulate the hospital itself on its 164th anniversary. Wow. Will you still need me, will you still feed me, when I’m 164?”
Sir Paul has a long history of supporting GOSH, including paying a surprise visit to the wards, performing karaoke sessions with patients and attending the hospital’s annual Christmas party for patients.
GOSH chaplain and Beatles fan Jim Linthicum said: “Sir Paul McCartney is a genius as a musician and I have so much respect for him. He transcends the generations with his music and keeps us young. It’s a real honour to get a birthday message from such a legend. Sir Paul has touched so many people throughout the years with his music, a bit like GOSH, which also touches everybody, so it seems fitting to have him supporting the Give to GOSH appeal.”
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