OBJECTIVES: We identify and quantify implementation challenges and associated costs (inefficiencies) when switching vaccines on National Immunization Programs (NIPs) considering a scenario of three vaccines where: Vaccine A is the current standard of care, Vaccine B is imminently available, one year prior to Vaccine C, and Vaccine A and C are produced by the same manufacturer.

METHODS: A literature review was conducted to identify inefficiencies and associated costs. Inefficiencies were categorized as (1) general/programmatic-related (e.g., logistical, and practical) (n=11), or (2) manufacturer-related (e.g., packaging, and new partnerships) (n=7). Health system costs were separated into eight components. A closed response self-complete survey was developed and administered to vaccine experts (pediatricians, payers, pharmacists, internal medicine experts, and general practitioners) in Canada (n=10), France (n=10), Italy (n=10), Spain (n=11), and United Kingdom (UK) (n=12). For each category, inefficiencies were ranked from most to least important. For each cost component, a Likert scale (very likely, likely, unlikely, very unlikely) was used to determine whether switching twice versus once is associated with higher system costs.

RESULTS: 53 participants responses were collected. Experts ranked clinical considerations, updating immunization plans/policies, and scheduling routine immunization campaigns, as the three most important program inefficiencies. The three most important manufacturer-related inefficiencies were changes to existing schedule, updating internal systems, and reliability in delivery. For all eight cost components, participants tended to respond with ‘very likely’ or ‘likely’, indicating more costs are created when switching twice versus once. Overall, 93% of participants indicated implementation costs were important when considering a vaccine switch.

CONCLUSIONS: Switching vaccines twice versus only once on a NIP over a short period, and switching vaccine manufacturers, are both associated with more inefficiencies and higher costs. In scenarios where multiple vaccines are licensed in short succession, decisions makers should consider waiting to assess vaccines simultaneously for inclusion in NIPs.