The Backstreet Boys announced today they had to cancel two appearances after member Brian Littrell was diagnosed with swine flu. The group will not appear for a scheduled autograph gig at today’s NYC Pinktober event at the Hard Rock Cafe, and will not perform on the CBS Early Show tomorrow morning. Other members Nick Carter, Howie Dorough, and AJ McLean all tested negative for H1N1, but were prescribed Tamiflu as a precautionary measure. Their new album, This Is Us, is available starting tomorrow.