This correspondence, published in the Lancet Global Health, reviews a research article estimating that vaccines against major diarrhoeal pathogens would lead to only modest reductions in overall antibiotic use. It argues that existing models only account for antibiotics avoided through the prevention of vaccine-preventable diarrhoeal episodes, while overlooking a major driver of antibiotic overuse: prescriber uncertainty. Many antibiotics given for diarrhoea are prescribed despite the absence of confirmed bacterial infection, often due to limited diagnostic capacity, clinician uncertainty, and pressure from patients or caregivers.
The authors argue that these estimates substantially underestimate the true potential impact of vaccination. Widespread use of effective vaccines against the main bacterial causes of diarrhoea could reduce clinicians’ uncertainty about bacterial infection, thereby decreasing not only pathogen-specific antibiotic use but also unnecessary antibiotic prescribing for diarrhoea overall, which accounts for nearly a quarter of antibiotic use in young children.
