>>> WELCOME BACK TO "GMA3." DR. JEN ASHTON JOINS US NOW LIVE IN LOS ANGELES. >> YEAH, AND DR. JEN, WE GOT A LOT TO TALK ABOUT. THERE'S AN UPDATED BOOSTER THAT HAS SHOWN TO BE EFFECTIVE FOR THOSE FULLY VACCINATED? >> RIGHT. SO, THE CDC JUST RELEASED SAYING THEIR LATEST DATA ON THE BIVALENT COVID-19 BOOSTER, THEY LOOKED AT HEALTHY, NONIMMUNE COMPROMISED ADULTS IN THE U.S. FROM EARLY DECEMBER THROUGH MID-JANUARY AND REALLY TRACKED, DID THEY GET INFECTED WITH COVID-19, THIS NEW VARIANT? AND IF THEY DID, HOW SICK? AND DID THEY RECEIVE THE BOOSTER? WERE THEY VACCINATED? WERE THEY COMPLETELY UNVACCINATED? AND THE DATA ON THIS BIVALENT BOOSTER, YOU GUYS, IS REALLY GOOD, SHOWING 52% EFFICACY IN SYMPTOMATIC COVID-19. SO, REMEMBER, THAT'S NOT 52% EFFECTIVE IN PREVENTING US FROM GETTING INFECTED AT ALL. IT'S JUST SEVERELY ILL. AND THAT'S REALLY IMPORTANT. THAT IS ESTIMATED TO RESULT IN SAVING THOUSANDS OF LIVES DUE TO COVID-19. SO, AGAIN, STILL TIME TO GET BOOSTED, BUT THE DATA LOOKS PRETTY GOOD ON THIS NEW BIVALENT BOOSTER. >> I KNOW THESE WERE SELF-REPORTED RESULTS. WHAT DOES THAT MEAN, AS FAR AS THE ACCURACY GOES? >> WELL, I MEAN, NOW YOU'RE THINKING LIKE AN EPIDEMIOLOGIST. IT'S IMPORTANT, BECAUSE OBVIOUSLY, WHEN SELF-REPORTING IS IN THERE, THERE CAN BE BIAS, THERE CAN BE WHAT'S CALLED COLLECTION BIAS, OR SELECTION BIAS, BUT STILL, RIGHT NOW, IT'S JUST IMPORTANT FOR US TO GET DATA ON HOW THESE VACCINES AND BOOSTERS ARE BEHAVING IN THE REAL WORLD AND ANALYZE THAT DATA AND REPORT THAT DATA, SO, BOTTOM LINE, IT'S REALLY HOLDING UP PRETTY WELL AGAINST THE NEW VARIANT. >> ALL RIGHT, DR. JEN, THANK YOU. YOU'RE A DOCTOR NOW, RHIANNON, OKAY.