Re-evaluating the potential impact and cost-effectiveness of rotavirus vaccination in 73 Gavi countries: a modelling study

Frédéric Debellut,Andrew Clark,Clint Pecenka,Jacqueline Tate,Ranju Baral,Colin Sanderson,Umesh Parashar,Laura Kallen,Deborah Atherly

doi:10.1016/s2214-109x(19)30439-5

Abstract

SummaryBackgroundPrevious studies have found rotavirus vaccination to be highly cost-effective in low-income countries. However, updated evidence is now available for several inputs (ie, rotavirus disease mortality rates, rotavirus age distributions, vaccine timeliness, and vaccine efficacy by duration of follow-up), new rotavirus vaccines have entered the market, vaccine prices have decreased, and cost-effectiveness thresholds have been re-examined. We aimed to provide updated cost-effectiveness estimates to inform national decisions about the new introduction and current use of rotavirus vaccines in Gavi countries.MethodsWe calculated the potential costs and effects of rotavirus vaccination for ten successive birth cohorts in 73 countries previously and currently eligible for Gavi support, compared with no vaccination. We used a deterministic cohort model to calculate numbers of rotavirus gastroenteritis cases, outpatient visits, hospitalisations, and deaths between birth and 5 years, with and without rotavirus vaccination. We calculated treatment costs from the government and societal perspectives. The primary outcome measure was the incremental cost-effectiveness ratio (discounted US$ per disability-adjusted life-year averted). Country-specific model input parameters were based on the scientific literature, published meta-analyses, and international databases. We ran deterministic and probabilistic uncertainty analyses.FindingsOver the period 2018–27, rotavirus vaccination has the potential to prevent nearly 600 000 deaths in Gavi countries. Averted outpatient visits and hospitalisations could lead to treatment savings of approximately $484·1 million from the government perspective and $878·0 million from the societal perspective. The discounted dollars per disability-adjusted life-year averted has a very high probability (>90%) of being less than 0·5 times the gross domestic product per capita in 54 countries, and less than 1·0 times gross domestic product per capita in 63 countries.InterpretationRotavirus vaccination continues to represent good value for money across most Gavi countries despite lower rotavirus mortality estimates and more stringent willingness-to-pay thresholds.FundingBill & Melinda Gates Foundation.

Highlights

Added value of this study Our study provides an update on the cost-effectiveness of rotavirus vaccination in previous and current Gavi-eligible countries
Implications of all the available evidence Our study provides evidence that rotavirus vaccination is still a cost-effective investment in Gavi countries
Alternative scenarios and probabilistic analysis In addition to our base-case scenario covering countries with the vaccine they were using in 2018, or a randomly allocated vaccine (Rotavac or Rotasiil) for countries that were not using rotavirus vaccine at the time of analysis, we explored alternative scenarios looking at the use of Rotarix, Rotavac, and Rotasiil in all Gavi countries

Summary

Introduction

Introduction yearAfghanistan Angola Armenia Bolivia Burkina Faso Burundi Cameroon Côte d’Ivoire Djibouti Eritrea Ethiopia Georgia Ghana Guinea-Bissau Guyana Haiti Honduras India* Kenya Kiribati Lesotho Liberia Madagascar Malawi Mali Mauritania Moldova Mozambique Nicaragua Niger Pakistan Republic of Congo Rwanda São Tomé and Príncipe Senegal Sierra Leone Sudan Tajikistan Tanzania The Gambia Togo Uganda Uzbekistan Yemen Zambia ZimbabweRotarix Rotarix Rotarix Rotarix RotaTeq Rotarix Rotarix RotaTeq Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotavac/Rotasiil Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix RotaTeq Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix RotaTeq Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix Rotarix RotarixThese data are for countries already using rotavirus vaccines at the end of 2018; countries not using rotavirus vaccines at the end of 2018 were randomly allocated one of the newly prequalified vaccines. *Assuming that 50% of immunised children are receiving Rotavac and the other 50% Rotasiil.Coverage of each dose of rotavirus vaccine is based on the WHO–UNICEF estimates of national immunisation coverage.[28]. Data for vaccine coverage timeliness were taken from Clark and colleagues.[25] Assumptions about vaccine efficacy and waning were based on pooled data from published randomised controlled trials of rotavirus vaccines that are described elsewhere.[40] In brief, in settings with medium under-5 mortality (defined as 13·5–28·1 deaths per 1000 livebirths) pooled efficacy was 82% (95% credibility interval 74–92%) after 2 weeks of follow-up and 77% (67–84) after 12 months, based on 11 observations. In settings with high under-5 mortality (defined as >28·1 deaths per 1000 livebirths) pooled efficacy was 66% (95% credibility interval 48–81) after 2 weeks of follow-up and 44% (27–59) after 12 months, based on 24 observations. We did not apply any age restriction to the vaccine schedule.[41]

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