CDC published Interim Estimates of 2018–19 Seasonal Influenza Vaccine Effectiveness—United States, February 2019 in the February 15 issue of MMWR (pages 135–139). A summary made available to the press is reprinted below.
CDC recommends yearly influenza vaccination for children at least 6 months old and adults. Early estimates indicate that influenza vaccines have reduced the risk of medically attended influenza-related illness by almost half (47%) in vaccinated people so far this season. Vaccination reduced the rate of illness caused by the predominant influenza H1N1 virus by about 46 percent among patients of all ages, and by about 62 percent among children 6 months through 17 years of age. Vaccination provided similar protection to that seen in previous H1N1 seasons in children and in adults younger than age 50. For these estimates, 3,254 children and adults with acute respiratory illness were enrolled from November 23, 2018 to February 2, 2019 at five study sites with outpatient medical facilities in the United States.
Influenza activity continues to increase in the U.S. with six additional pediatric deaths from influenza reported, for a total of 34 as of February 9. Please continue to vaccinate all your patients six months of age and older.