Data show that the flu vaccine did a poor job of protecting older adults, ages 65 and older, from the illness last winter. Results were presented by the Advisory Committee on Immunization Practices—a group of health experts that provide recommendations regarding the use of vaccines in the United States—and showed that the vaccine was only 42% effective in preventing individuals from being affected enough by the flu to need to go to the doctor.
While the vaccine proved 60% effective in protecting young children and was somewhat effective in protecting individuals ages 50-64, the illness hit individuals ages 65 years and older much harder, with the vaccine proving to be nearly ineffective for this vulnerable group. Hospitalization rates due to flu-related symptoms sky rocketed this past winter, hitting the highest they’ve been since the 2014-2015 flu season.
This past winter’s flu—Type A H3N2—is considered severe, and tends to cause more deaths and serious illnesses than any other flu viruses.
Of note, vaccines against other infectious diseases must reach at least 90% effectiveness in order to be considered successful. For the flu vaccine, however, effectiveness has averaged only about 46% in the last ten years.
Officials at the Centers for Disease Control said they are investigating whether past flu vaccinations affected how well the most recent flu vaccine worked. They are also looking into whether different brands of the vaccine offer better protection than others.