COVID cases driven by "flirt" subvariants on the rise

New data indicates COVID cases are on the rise in California, driven by a series of new strains of the virus known as "flirt" subvariants. As we head towards summer, those more transmissible subvariants have now overtaken the previous winter strain. KTVU's Alex Savidge speaks with Dr. Peter Chin-Hong, infectious disease expert at UCSF about effective our current COVID vaccines are against the new strains.