Cases of reinfection, questionable testing guidelines and more on plasma therapy — catch up on this week's COVID-19 news with Live Science! Hong Kong reinfection: https://www.livescience.com/coronavirus-confirmed-case-reinfection.html US reinfection: https://www.livescience.com/coronavirus-reinfection-case-confirmed-us.html Testing guidelines: https://www.livescience.com/cdc-covid-19-testing-guidelines-change.html Plasma: https://www.livescience.com/fda-issues-emergency-authorization-plasma-therapy-for-covid.html Science News • Videos • Explainers SUBSCRIBE to the Live Science YouTube channel → http://www.shorturl.at/fzCV5 Twitter→ https://twitter.com/LiveScience Facebook→ https://www.facebook.com/livescience Instagram→ https://www.instagram.com/live_science/ Community Forums→ https://forums.livescience.com/ For the science geek in everyone, LiveScience.com breaks down the stories behind the most interesting news and photos on the Internet, while also digging up fascinating discoveries that hit on a broad range of fields, from dinosaurs and archaeology to wacky physics and astronomy to health and human history. If you want to learn something interesting every day, #LiveScience is the place for you.