CA Notify only alerts when someone who has a positive test was believed to have been within 6 feet of someone else for at least 15 minutes. … “It’s basically occupational exposure,” said Andrew Noymer, an epidemiologist and associate professor of population health at UC Irvine. Noymer said it was impressive that so many people activated or downloaded the app. He didn’t fault the state for trying but said it “was not a game-changer.” “It should be a cautionary tale for how far we’re going to be able to ‘tech’ our way out of the pandemic,” Noymer said. He has the app himself but has never gotten an alert, he said.