Flu Vaccination Setting Impacts When Individuals Will Get Their Shots

US Centers for Disease Control and Prevention (CDC) recommendations indicate that everyone 6 months of age and older should receive their flu shot every season by the end of October; however, individuals still choose to opt out, putting themselves at risk for infection.

Now, investigators have found that certain vaccination settings increase the odds of receiving a flu shot before the end of October and certain factors influence when and where patients will receive their vaccinations. Results from the survey were presented at the 2018 ID Week Annual Meeting in San Francisco, CA.

Megan Luther, PharmD, College of Pharmacy, University of Rhode Island, and her team set out to assess the association between timing and setting of influenza vaccination.

To do this, they referred to the 2015 Behavioral Risk Factor Surveillance System (BRFSS), which allowed them to identify adults in the United States who reported having received a flu shot in the past year.

By looking at self-reported dates of when participants received their flu shots, Luther and her team divided up the 2014-2015 flu season into early (July to October) versus late (November to May) vaccination.

They also reviewed where participants received their shots—doctor’s offices, clinics/hospitals, stores, and work.

The investigators also noted demographics, if participants had a checkup within the past year, if they had insurance, if they were obese (BMI ≥30), their alcohol use and smoking habits, as well as comorbidities (categorized as 0, 1 to 2, or 3+ present: hypertension, high cholesterol, stroke, angina, heart attack, skin cancer, other cancer, arthritis, depression, kidney disease, diabetes, asthma, and chronic obstructive pulmonary disease).

Of 130,615 patients included in the analysis, Luther and her team found that patients who received their vaccinations at doctor’s offices and stores were older and had higher rates of comorbidities than those who received their vaccinations in clinics or at work.

Patients between the ages of 18 and 64 had higher odds of getting vaccinated earlier at clinics (odds ratio (OR) 1.11, 95% confidence interval (CI) 1.02-1.22), stores (OR 1.09, 95% CI 1.002-1.19), and work (OR 1.88, 95% CI 1.71-2.05) compared with doctor’s offices, per age-stratified analyses. Patients who were 65 years of age or older had higher odds of getting vaccinated at stores (OR 1.17, 95% CI 1.07-1.27) and work (OR 1.67, 95% CI 1.33-2.09).

They also noted that males, smokers, and those who had children had lower odds of getting vaccinated early.

“Vaccination setting is associated with vaccination timing: non-traditional (store, work) settings increase the odds of receiving a flu shot before the end of October,” Luther and colleagues wrote. “Age plays a key role in when and where patients receive flu vaccinations.”

Adults over the age of 65 need to receive a flu shot for several reasons. In a past interview with our sister publication, Contagion^®, William Schaffner, MD, medical director of the National Foundation for Infectious Diseases, explained why.

“People aged 65 and older have a diminished immune system. It doesn’t work as well; it’s not as responsive as the immune system in younger people, and so, they are disproportionately made ill, they get more serious illness when they’re infected with influenza,” he said.

Timing of vaccination for the flu is vital since those in this high-risk population could be at risk for intraseason immunity waning.

Although traditionally, flu vaccinations would typically be given in doctor’s offices, other settings are increasing the availability and convenience of these vaccines. In non-traditional settings, vaccination programs should consider targeting the later flu season to increase participation, the authors conclude.

The abstract, "Impact of influenza vaccination setting on timing of vaccination in a national sample of influenza-vaccinated adults," was presented at ID Week 2018.