Selena Gomez, who once told us she feels like a "big sister" to Bieber, added that her loyalty runs very deep. But does she have the fever? "Of course! I do, absolutely, yes!"
Nickelodeon star Victoria Justice, whose new show "Victorious" premiered after the KCAs, added her name to the infected list. "Oh, man! Bieber fever, man, call the doctor. I got it bad!" she quipped.
Meanwhile, actress Jasmine Villegas, Bieber's love interest in the "Baby" music video, seemed to have a much milder case. "Of course, he's, like, a really cool friend of mine," she said. "But he's definitely super talented."
There have been some reported cases among male Bieber fans too. Boys Like Girls lead singer Martin Johnson said, "I think he's the man." And Bieber's "Eenie Meenie" collaborator, Sean Kingston, is happy that so many people have the fever these days. "That's my little bro," he said. "I'm gonna support him and be excited for him."
Bieber said he appreciates all the support his fans and other celebrities have shown him since being catapulted to superstar status. "It feels great," he said at the KCAs. "I'm just happy to be here, happy to have so many supportive fans."
Do you have Bieber fever? Tell us your symptoms in the comments!