The CDDEP team walked over to our corner drugstore today for our annual flu shots. In addition to improving our odds of avoiding many of the influenza strains circulating this year, we also reduced the chances that we will need antibiotics this flu season.
How does vaccination against influenza— a virus—reduce antibiotic use? The answer is twofold.
First, many doctors prescribe (and many patients request) antibiotics to treat common flu symptoms such as coughs and runny noses. While some infections that cause these symptoms are bacterial, flu is caused by influenza viruses, which do not respond to antibiotics. By preventing flu and its symptoms, the chance that antibiotics will be unnecessarily prescribed is reduced. Researchers have estimated that reducing influenza activity by 20 percent reduces antibiotic prescriptions by 8 percent[1].
Second, preventing influenza also prevents the pneumonia (both bacterial and viral) that occurs as a secondary infection following influenza. Secondary bacterial co-infections are a major cause of death, and require antibiotic treatment. The risk of influenza-associated pneumonia has also been shown to be lower in those vaccinated against influenza[2].
The CDC estimates that more than 200,000 people are hospitalized every year in the United States due to complications from seasonal influenza infections, including the direct effects of the virus and secondary infections. The flu vaccine can prevent more than 70 percent of these hospitalizations[3].
We are fortunate in the United States to have easy access to the influenza vaccine in pharmacies, clinics and doctors offices. The vaccine is covered by most insurance plans and is relatively inexpensive even out-of-pocket. We hope you will join us in an influenza-free—and antibiotic-free—winter.
Molly Miller Petrie is a Senior Research Analyst at CDDEP.

[1] Polgreen PM, Yang M, Laxminarayan R, Cavanaugh JE. Respiratory fluoroquinolone use and influenza. Infect Control Hosp Epidemiol [Internet]. 2011;32(7):706–9. Available from: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3258490&tool=pmcentrez&rendertype=abstract
[2] Grijalva, C. G., Zhu, Y., Williams, D. J., Self, W. H., Ampofo, K., Pavia, A. T., … Edwards, K. M. (2015). Association Between Hospitalization With Community-Acquired Laboratory-Confirmed Influenza Pneumonia and Prior Receipt of Influenza Vaccination. JAMA, 314(14), 1488. http://doi.org/10.1001/jama.2015.12160