Flu cases are increasing across the United States, with a dominant H3N2 strain particularly affecting older adults. While the current surge is not considered unusual and falls within historical patterns, health officials note a rise in flu-related hospitalizations and emergency room visits. Experts emphasize that vaccination remains effective in reducing severe illness, even if the vaccine is not a perfect match for the circulating strain. The season is not yet at its peak, which typically occurs in January or February.