[9:15 a.m. April 28: Editor's note — This original post inaccurately stated that the variant XBB.1.16 had not been detected locally by UW Medicine's Virology Laboratory. In fact, that variant had been identified among local virus samples (see "Omicron - Other XB) in this graph.]

Dr. Shireesha Dhanireddy thinks the bivalent COVID-19 booster formulation that came available last fall still provides ample protection against emerging virus variants, including Omicron XBB.1.16, or “Arcturus.” 

“We think that this booster still has activity against the newer virus that we're hearing about,” said Dhanireddy, a professor of medicine at the University of Washington School of Medicine.

The Centers for Disease Control and Prevention (CDC) recommends a second booster dose of the bivalent vaccine for people at highest risk of serious illness from COVID-19, including anyone over age 65 and  immunocompromised people 5 and older. 

“This is an extra layer of protection for you, particularly those who are immunocompromised that really don't have a strong immune response to the vaccine, but also not a strong immune response to fight off the infection,” Dhanireddy said. 

For people outside the CDC’s latest guidance who are current on their booster doses, Dhanireddy expects another booster to be announced sometime this fall. 

“As we know with the flu vaccine, we're always anticipating changes, and the (flu) vaccine is tweaked every year — and we may be doing that, maybe not every year, but maybe every few years or whenever needed, with the COVID-19 vaccine,” said Dhanireddy. 

Download broadcast-ready soundbites discussing current COVID-19 booster recommendations. 

Additional resource: UW Medicine COVID-19 Vaccination Information