E-Mail For public health officials, contact tracing remains critical to managing the spread of the coronavirus -- particularly as it appears that variants of the virus could be more transmissible. The need for widespread contact tracing at the start of the pandemic led tech giants Apple and Google to announce a plan to turn iOS and Android phones into mobile "beacons" that alert users who opt in of potential exposure to COVID-19. Health officials in some states have used the technology in their pandemic response efforts, as have other countries around the world, but researchers at the University of Notre Dame say contact tracing apps created by third-party developers could leave users vulnerable to a host of privacy and security issues.