Potential cost-effectiveness of a maternal Group B streptococcal vaccine in The Gambia

Abstract

ObjectiveTo estimate neonatal health benefits and healthcare provider costs of a theoretical Group B streptococcal (GBS) hexavalent maternal vaccination programme in The Gambia, a low-income setting in West Africa. MethodsA static decision analytic cost-effectiveness model was developed from the healthcare provider perspective. Demographic data and acute care costs were available from studies in The Gambia undertaken in 2012–2015. Further model parameters were taken from United Nations and World Health Organisation sources, supplemented by data from a global systematic review of GBS and literature searches. As vaccine efficacy is not known, we simulated vaccine efficacy estimates of 50–90%. Costs are reported in US dollars. Cost-effectiveness thresholds of one (US$473, very cost effective) and three (US$1420, cost effective) times Gambian GDP were used. ResultsVaccination with a hexavalent vaccine would avert 24 GBS disease cases (55%) and 768 disability adjusted life years compared to current standard of care (no interventions to prevent GBS disease). At vaccine efficacy of 70%, the programme is cost-effective at a maximum vaccine price per dose of 12 US$ (2016 US$), and very cost-effective at a maximum of $3/dose. The total costs of vaccination at $12 is $1,056,962 for one annual cohort of Gambian pregnant women. One-way sensitivity analysis showed that GBS incidence was the most influential parameter on the cost effectiveness ratio. ConclusionThe introduction of a hexavalent vaccine would considerably reduce the current burden of GBS disease in The Gambia but to be cost-effective, the vaccine price per dose would need to be $12/dose or less.