More States Offer Covid-19 Contact-Tracing Apps, But Adoption Is Uneven
Covid-19 contact-tracing apps from Apple Inc. and Google are coming to more states, along with evidence that they can help slow infections as long as enough people use them.
Fourteen states and Washington, D.C., have recently adopted the “exposure notification” technology the companies built into their smartphone operating systems—Big Tech’s most significant contribution to the fight against Covid-19. California, and other states are piloting the technology and could release it soon. It lets people who have tested positive…