New data suggest that influenza vaccines may reduce overall and inappropriate antibiotic use by decreasing the burden of influenza-like illness commonly mistreated with antibiotics, as well as preventing secondary bacterial infections, according to research from the Center for Disease Dynamics, Economics & Policy, Johns Hopkins University, and the University of Maryland School of Medicine.

Although flu vaccines have been proven to reduce severe illness, evidence is lacking on the link between flu vaccination and antibiotic prescribing at the population level in the United States, according to the study authors.

Researchers analyzed state-level data from IQVIA and the CDC’s FluVaxView on antibiotic prescribing rates and influenza vaccine coverage between January and March of each year from 2010 to 2017.

The study found that a 10% increase in influenza vaccination coverage was associated with a 6.5% reduction in antibiotic use or 14.2 fewer antibiotic prescriptions per 1000 individuals when utilizing fixed-effects regressing analysis adjusted for socioeconomic differences, access to health care, childcare centers, climate, vaccine efficacy, and state-level differences.

Further, increased vaccination rates were tied to significant reductions in antibiotic prescribing rates among pediatric (6%), elderly (5.2%), and adult populations (4.2%).

Across all ages, flu vaccine coverage was significantly and negatively associated with prescribing rates for macrolides, tetracyclines, narrow-spectrum penicillin, and aminoglycosides, all of which are antibiotic classes commonly prescribed for upper respiratory tract infections or severe infections, which flu vaccines prevent, according to the researchers.

"The flu is more common in children and the elderly, and thus this is fairly suggestive that the vaccine is limiting the severity of disease in these populations leading to lower rates of antibiotic prescribing," lead author Eili Klein said in a press release.

The results indicate that flu vaccination is associated with reduced antibiotic use in the United States, which suggests that expanding flu vaccine coverage could reduce inappropriate antibiotic prescribing, the study authors concluded.

Flu vaccine coverage linked to reduced antibiotic prescribing. EurekAlert! Published June 10, 2020. Accessed June 12, 2020.