In our continuing series looking at the latest medical research and news on COVID-19, Larry Mantle speaks with Kristen R. Choi, professor of nursing and public health at UCLA. 

Topics today include: 

• L.A. County to lift indoor mask mandate for vaccinated people on Friday. 

  • L.A. Unified drops outdoor mask mandate. 
• The U.S. mask mandate for air travel will expire next month, but some flight attendants say it’s too soon. 
• A new COVID vaccine shows 100% efficacy against severe disease and hospitalizations, its maker says. 
• Yes, millions of Americans have caught Omicron. No, we don’t have herd immunity. 

• Who might benefit from a fourth shot – and who might not. 

  • Got a COVID booster? You probably won’t need another for a long time. 
• New breakdown of hospitalized patients in California hospitals by vaccination status. 
• How Long COVID exhausts the body. 

This program is made possible in part by the Corporation for Public Broadcasting, a private corporation funded by the American people.