"Only about 4.4% of the US population that's eligible to receive the [new bivalent COVID-19] booster has gotten it. I've gotten mine. I urge everyone else to get it, because while it's not maybe perfect protection, it surely is some good protection for now. But at the same time, I'm watching very carefully kind of sleeping with one eye open to see what these new sub-variants that are highly immune evasive look like."