Incidence of Pharyngitis, Sinusitis, Acute Otitis Media, and Outpatient Antibiotic Prescribing Preventable by Vaccination Against Group A Streptococcus in the United States.

BACKGROUND: Group A Streptococcus (GAS) is a leading cause of acute respiratory conditions that frequently result in antibiotic prescribing. Vaccines against GAS are currently in development. METHODS: We estimated the incidence rates of healthcare visits and antibiotic prescribing for pharyngitis, sinusitis, and acute otitis media (AOM) in the United States using nationally representative surveys of outpatient care provision, supplemented by insurance claims data. We estimated the proportion of these episodes attributable to GAS and to GAS emm types included in a proposed 30-valent vaccine. We used these outputs to estimate the incidence rates of outpatient visits and antibiotic prescribing preventable by GAS vaccines with various efficacy profiles under infant and school-age dosing schedules. RESULTS: GAS pharyngitis causes 19.1 (95% confidence interval [CI], 17.3-21.1) outpatient visits and 10.2 (95% CI, 9.0-11.5) antibiotic prescriptions per 1000 US persons aged 0-64 years, annually. GAS pharyngitis causes 93.2 (95% CI, 82.3-105.3) visits and 53.2 (95% CI, 45.2-62.5) antibiotic prescriptions per 1000 children ages 3-9 years, annually, representing 5.9% (95% CI, 5.1-7.0%) of all outpatient antibiotic prescribing in this age group. Collectively, GAS-attributable pharyngitis, sinusitis, and AOM cause 26.9 (95% CI, 23.9-30.8) outpatient visits and 16.1 (95% CI, 14.0-18.7) antibiotic prescriptions per 1000 population, annually. A 30-valent GAS vaccine meeting the World Health Organization's 80% efficacy target could prevent 5.4% (95% CI, 4.6-6.4%) of outpatient antibiotic prescriptions among children aged 3-9 years. If vaccine prevention of GAS pharyngitis made the routine antibiotic treatment of pharyngitis unnecessary, up to 17.1% (95% CI, 15.0-19.6%) of outpatient antibiotic prescriptions among children aged 3-9 years could be prevented. CONCLUSIONS: An efficacious GAS vaccine could prevent substantial incidences of pharyngitis infections and associated antibiotic prescribing in the United States.