Extended Data Table 2 Lassa vaccination scenarios
From: Health and economic impacts of Lassa vaccination campaigns in West Africa
- Scenario 1 includes reactive vaccination only, which is triggered in response to local outbreaks, whereas the remaining scenarios 2–6 include preventive vaccination campaigns in addition to reactive vaccination. Vaccination coverage refers to the percentage of the general population targeted for vaccination in specified districts. Preventive vaccination in scenarios 2–4 is unconstrained—that is, the number of doses reflects desired vaccination coverage levels—whereas preventive vaccination is constrained in scenarios 5 and 6—that is, population coverage is constrained by an upper limit of doses to reflect a limited global vaccine stockpile (Supplementary Table C.2). The small vaccine pool reserved for reactive vaccination (1 million doses annually, shared across all districts proportionately to population size) is available immediately from year 1, whereas vaccination for preventive campaigns is rolled out to different countries in different years, generally to high-endemic, medium-endemic and low-endemic countries in years 1, 2 and 3, respectively (Supplementary Table C.3). A map showing the classification of endemicity across the countries and districts of West Africa is given in Fig. 1. For both reactive and preventive vaccination, booster doses are allocated 5 years after the initial dose, and 90% of available doses are assumed to be delivered (that is, all coverage targets were reduced by 10% wastage).
