This season’s flu vaccine has been 48% effective at preventing flu-related outpatient visits for acute respiratory illness, the Centers for Disease Control and Prevention estimates. More specifically, the vaccine has been 43% effective against the predominant influenza A virus (H3N2) and 73% effective against the influenza B virus. Flu-associated hospitalizations have been substantially lower than in 2014-15, when the same influenza A virus predominated, which may be due to a better match between this year’s vaccine and virus. According to the CDC’s latest report on flu activity, about 6,800 flu-associated hospitalizations were reported through Feb. 4, with 60% involving patients 65 or older. Flu activity is likely to continue for several more weeks, and vaccination efforts should continue as long as flu viruses are circulating, the authors said. Patients who require hospitalization or are at high risk for flu complications should be treated with flu antiviral medications as soon as possible, they said.