Vaccine impact on antimicrobial resistance to inform Gavi, the Vaccine Alliance's 2018 Vaccine Investment Strategy: report from an expert survey.

While the rise of antimicrobial resistance (AMR) has been recognised as a major public health problem, the value of vaccines to control AMR is poorly defined. This expert survey was launched with the aim of informing the 2018 Vaccine Investment Strategy through which Gavi, the Vaccine Alliance prioritises future vaccine funding. This exercise focused on both vaccines currently supported by Gavi and under consideration for future funding. The relative importance of pre-defined criteria as drivers of overall value of vaccines as a tool/ intervention to control AMR was assessed by 18 experts: prevention of mortality and morbidity due to resistant pathogens, antibiotic use prevented, societal impact, ethical importance and sense of urgency. For each vaccine, experts attributed scores reflecting the estimated value for each criterion, and overall value relative to AMR was derived from the value assigned to each criterion and their relative importance for each vaccine. Mortality, morbidity due to targeted resistant pathogens, and antibiotic use prevented were considered the most important determinants of overall value. Pneumococcal, typhoid and malaria vaccines were assigned highest value relative to antimicrobial resistance. Intermediate value was estimated for specific rotavirus, cholera, respiratory syncytial virus (RSV), influenza, dengue, measles, meningitis and type b- (Hib-) containing pentavalent vaccines. Lowest value relative to AMR was estimated for Japanese encephalitis, hepatitis A, yellow fever, rabies and human papilloma virus vaccine. In the future, more evidence-based, data-driven, robust methodologies should be developed to guide coordinated, rational decision making on priority actions aimed at strengthening the use of vaccines against AMR.