The flu season is well underway, and the State Department of Health has already been an active one so far in Northern California. Test rates have been trending up–especially among kids. That’s part of a nationwide trend, driven by a new variant of the seasonal flu. So far, hospitals haven’t seen a big increase in flu patients, but that is expected to change with more cases likely after the holidays and the peak of flu saeson which is usually in January or February. It’s not too late to get a shot–but the CDC says it takes about two weeks for full immunity to build.