Health experts have been tracking a new variant of COVID-19 they say is nearly twice as contagious as previous strains and causing more breakthrough infections. That strain is called the delta variant.  First identified in India, the delta variant is now the dominate strain in Arizona. What is the delta variant? What does it mean for us? Are vaccines mitigating community spread of the variant?In this week's episode of Valley 101, a podcast from The Arizona Republic and azcentral.com, we answer those questions. Learn more about your ad choices. Visit megaphone.fm/adchoices