Last year, the Centers for Disease Control and Prevention warned that too few patients above the age of 50 were getting vaccinated against the flu.
Researchers analyzed more than 350,000 visits by patients ages 50 and older to 12,000 primary care providers between July and October. About 16 percent of those visits included a flu shot. Over the same period last year, 14 percent of primary care visits from patients 50 and older included a flu shot.
For the population of patients 65 years and older, the trend lines were similar. Approximately 16 percent of this sample population's visits to a primary care doctor included a flu shot by the end of October.
Visits to urgent care offices, community health centers, and pharmacies were not included in the analysis, though CDC research suggests that adults are more likely to get a flu shot from if they have a regular provider.
One potential factor in this year's low immunization rates: The CDC called for seniors to wait until after Halloween to get vaccinated this year, in order to increase their immunity when the flu season picks up between December and March.
Still, the data "highlights the need for increased understanding about how to increase vaccination rates in this group," says Kimberly Shea, Ph.D., an epidemiologist at Boston University.
And that lack of adherence can have serious consequences. Recent studies estimate that patients 65 and older represent as much as 70 percent of flu-related hospitalizations and 85 percent of flu-related deaths.
Shea notes that childhood vaccination rates are the subject of much more clinical research and media attention, while older adult and senior vaccination rates are not.
"I'm not surprised [by this data]," she says, "because there haven't been any major changes from last year to this year in the way we are promoting vaccinations."
athenaInsight is tracking the spread of the flu throughout the 2016-17 season, with weekly updates on diagnoses and vaccination rates.
Chelsea Rice is a staff writer for athenaInsight. Data analysis by Stewart Richardson.