Am I contagious? U.S. health officials have dropped five-day isolation guidelines for people who get covid, prompting a mix of relief and confusion. Today, The Post’s Lena Sun breaks down what’s behind the shift. Plus, the latest on measles in Florida.On Friday, the Centers for Disease Control and Prevention announced that, effective immediately, people who test positive for the coronavirus no longer need to stay home for five days. Instead, the agency recommends that you stay home when sick, but if symptoms improve and you’re fever-free for at least 24 hours without taking any meds, you no longer have to isolate. The updated guidelines put covid-19 in line with many other viral respiratory diseases. For many, the change is both practical and overdue. Yet, covid continues to send thousands of people to the hospital each week, causing some 2,000 deaths, further raising alarms among high-risk patients.Today on “Post Reports,” Lena Sun, who covers infectious diseases and public health, unpacks what’s behind the new guidance, how to stay healthy, and why the response to a completely different infectious disease – measles – is sounding new alarms. Read more:When you have covid, here’s how you know you are no longer contagious.What to know about the recent measles outbreak, and signs to watch for.CDC recommends older adults get 2nd updated coronavirus shot.Dr. Paul Offit also spoke with Lena Sun about his new book, "Tell Me When It's Over,” for this episode and for The Health 202 newsletter.  Today’s show was produced by Emma Talkoff, with help from Elana Gordon. It was mixed by Sean Carter. It was edited by Maggie Penman. Thanks to Fenit Nirrapil. Subscribe to The Washington Post here.