A review of the effect of immunization programs on antimicrobial utilization.

The objective of this review is to summarize and evaluate the literature pertaining to antimicrobial utilization with respect to implementation of immunization programs or within clinical studies assessing vaccine effectiveness. A literature search was performed using the search terms vaccine; immunization; antimicrobial; antibiotic; influenza; pneumococcal; haemophilus; meningococcal in MEDLINE (1948-May 2012), EMBASE (1980-May 2012), International Pharmaceutical Abstracts (1970-May 2012), Google, and Google Scholar. Identified clinical or epidemiological studies were included if antimicrobial utilization was listed as a reported outcome. Seven articles (three randomized controlled trials and four epidemiological studies) were identified and included in the review. These studies reported outcomes associated with pneumococcal and influenza immunization programs. All studies reported decreased antibiotic use associated with initiation of immunization programs or increased uptake of available vaccines. Large-scale epidemiological studies confirm population-wide decreases observed from short-term randomized controlled trials. Antibiotic reductions ranged from 5 to 10% in randomized controlled trials to relative reductions of 64% in epidemiological studies. These findings suggest that immunization programs may reduce antibiotic utilization. As such, vaccination status queries and updates should become part of routine care for both hospitalized and non-hospitalized patients. Immunization programs should be considered as part of institution-wide antimicrobial stewardship programs.