OBJECTIVES: Lagging policies for immunization in ageing adults, low vaccine uptakes, and the lack of supportive evidence at the national level could diminish the impacts on health and economics of such programs. This study aims to (i) develop a country score tool designed to assess readiness and facilitate evidence generation with regards to ageing adult immunization programs in Europe, and (ii) examine the comprehensiveness, relevance, acceptability, and feasibility of the tool.

METHODS: An initial set of 14 items generated from a literature review and a stakeholder consultation was evaluated in a three-round online Delphi study. Survey links were sent to the supra-national and national decision-makers of immunization programs recruited from five countries using a mix of purposive and snowball sampling method. The consensus was predefined at the agreement rate of 70%. The pilot test was conducted in the Netherlands, Germany, Serbia, and Hungary involving researchers in the field of health technology assessment. After assessing the country’s readiness, researchers evaluated four features of the tool via an online survey that included 5-scale Likert questions. Percentage of affirmative answers including “agree” and “totally agree” choices were presented.

RESULTS: Eight experts were involved in the Delphi panel. Through three rounds, four items were added, one was dropped, and all others were amended. The consensus was achieved on the tool with 17 items divided into decision-making and implementation parts. Each item has a guiding question, corresponding to explanations and rationales to inform assessment with readiness scores. Eight researchers completed the pilot test. The tool was rated as comprehensive (75%), relevant (100%), acceptable (75%), and feasible (88%) by participants.

CONCLUSIONS: We have developed the country score tool and examined its features through a thorough and transparent process. The tool can help to identify strengths, weaknesses, and needed evidence for decision-making and implementation of ageing adult immunization programs in Europe.