In our continuing series looking at the latest medical research and news on COVID-19, Larry Mantle speaks with infectious diseases physician and professor of medicine at UCSF Dr. Monica Gandhi. 

Topics today include: 

• C.D.C. says post-infection immunity was very effective against Delta, but vaccines still offer the best defense. 
• Omicron leaves testing labs overwhelmed, causing frustrating delays to get results. 
• Even as Omicron starts to ease in California, hospitals facing grim conditions. 
• California approaches pandemic record for all hospitalizations. 
• Why are men more likely to die of COVID-19? It’s complicated. 
• Can vaccinated people who get a breakthrough infection start living like it’s 2019? 
• As L.A. schools backtrack on COVID vaccine, dozens more districts push to mandate it. 

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