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1 | This document was recreated in February 2021 from GiveWell's 2017 preliminary estimate of the cost-effectiveness of measles vaccination (original version can be downloaded here). The "Results" section of the "MAIN" sheet was updated to incorporate our updated moral weights (see "Value assigned to averting the death of an individual under 5 due to measles") and to estimate the relative cost-effectiveness of supplementary immunization activities verses cash transfers. No other aspects of the spreadsheet were updated. This CEA is significantly less developed than many of GiveWell's published cost-effectiveness analyses. However, as we were unable to identify room for additional funds for measles vaccination of children under 5, we have not further refined or finalized this model. | ||||||||||||||||||||||||
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3 | 1. Inputs | ||||||||||||||||||||||||
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5 | Inputs for MCV1 coverage, MCV2 coverage, and case fatality ratio are for the following country: | ||||||||||||||||||||||||
6 | Uganda | ||||||||||||||||||||||||
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9 | Parameter | Inputs | Parameter explanation | Key data source | For further explanation and sources, see: | ||||||||||||||||||||
10 | MCV1 coverage | 82.00% | Proportion of 9-month-olds who received measles vaccination through routine health systems. | WHO/UNICEF Estimates of National Immunization Coverage by country (1980-2013) (HTML) | http://www.givewell.org/node/2472 - routineimmunization | ||||||||||||||||||||
11 | MCV1 effectiveness | 85.00% | Effectiveness of vaccine at 9mo. | Cutts, Grabowsky, and Markowitz 1995, a review of 30 studies of vaccine efficacy in infants under 9 months. | http://www.givewell.org/node/2472#vaccine | ||||||||||||||||||||
12 | MCV2 coverage | 0.00% | Proportion of children who receive measles vaccination at 18mo or later. SIAs tend to target countries with little or no MCV2 coverage. | WHO/UNICEF Estimates of National Immunization Coverage by country (1980-2013) (HTML) | http://www.givewell.org/node/2472 - routineimmunization | ||||||||||||||||||||
13 | MCV2 effectiveness | 95.00% | Effectiveness of vaccine at >12mo. | Demicheli et al. 2012, a Cochrane review of MMR vaccine effectiveness based on three cohort studies. | http://www.givewell.org/node/2472#vaccine | ||||||||||||||||||||
14 | How many years ago was the most recent SIA? | 3.00 | Suggested values: 3 or N/A. A current SIA would have an under-5 target populaion which overlaps with the under-5 target population of any SIA conducted in the last 4 years. Many countries schedule SIAs every 2-4 years depending on measles epidemiology and SIA coverage rate. Select 0, 1, 2, 3, 4 years or N/A. | WHO Retrospective Measles Data on Supplementary Immunization Activities 2000-2015 (Excel 262kb) | http://www.givewell.org/node/2472#Whatistheprogram | ||||||||||||||||||||
15 | SIA coverage | 90.00% | SIAs are often estimated to reach about 95% of their target population. Data on SIA coverage rates is of very limited quality. This parameter is used both for the current SIA under evaluation and for the previous SIA (if applicable). | WHO Retrospective Measles Data on Supplementary Immunization Activities 2000-2015 (Excel 262kb) | http://www.givewell.org/node/2472#SIAcoverage | ||||||||||||||||||||
16 | Under-5 case fatality ratio | 3.00% | Proportion of cases in children under 5 years of age resulting in death. WHO estimates the range of measles CFRs in low-income countries to be between 0.05% and 6%, and between 10% and 30% in complex emergencies or in isolated areas where there is low natural immunity or low vaccination coverage. (We assume case fatality ratio of 0 at ages 5 and up.) The lookup formula returns the lower bound of estimated CFR; see sheet "CFR" column D for upper bounds. | Wolfson et. al 2009, a WHO estimate of measles case fatality ratios based on expert opinion | http://www.givewell.org/node/2472#CFR | ||||||||||||||||||||
17 | Annual chance of contracting measles if susceptible | 30.00% | Used in calculating susceptibility (those who have previously contracted measles become immune) and deaths. The WHO Measles Strategic Planning Tool assumes that susceptible individuals have a 30% chance per year of becoming infected with measles, so long as population immunity is less than 90%. We do not include herd immunity effects in this model (e.g. we assume that populations where SIAs occur have not achieved herd immunity). This highly uncertain parameter has a large effect on cost-effectiveness. | The WHO Measles Strategic Planning (MSP) Tool, as discussed in Simons et al. 2011 | http://www.givewell.org/node/2472#infectiousness | (Derived): Monthly chance of contracting measles if susceptible | 3% | ||||||||||||||||||
18 | SIA cost per person targetted (2015USD) | 2.7 | We are somewhat uncertain about the cost per person targeted. See discussion and data sources. | http://www.givewell.org/node/2472#cost | http://www.givewell.org/node/2472#cost | ||||||||||||||||||||
19 | SIA proportion of target population under 5 years of age | 100% | Suggested values: 100%, 33%. Some SIAs ("follow-up SIAs") target only children under five. Others target a wider age range (such as: under-15s). Because death from measles primarily (in this model: only) occurs in children under five, this parameter affects the total cost of an SIA but not the deaths averted. Vary this parameter to model the relative cost-effectiveness of SIAs targeting only under-5s vs SIAs targetting a wider population. | WHO Retrospective Measles Data on Supplementary Immunization Activities 2000-2015 (Excel 262kb) | http://www.givewell.org/node/2472#Whatistheprogram | ||||||||||||||||||||
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22 | 2. Calculations | ||||||||||||||||||||||||
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24 | What proportion of children between 9mo and 5yo are susceptible to measles at the time of the SIA? | ||||||||||||||||||||||||
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26 | Immunized by surviving measles | ||||||||||||||||||||||||
27 | Age cohort (months) | Immunized by MCV1 | Immunized by MCV2 | Immunized by prior SIA (depends on SIA year above) | Average months alive | Portion of susceptibles who have had measles by this age | Immunized by surviving measles | Unimmunized | Weight of age cohort | ||||||||||||||||
28 | 9-18 | 70% | ineligible | ineligible | 13.5 | 33% | 10% | 21% | 18% | ||||||||||||||||
29 | 18-21 | 70% | 0% | ineligible | 19.5 | 44% | 13% | 17% | 6% | ||||||||||||||||
30 | 21-33 | 70% | 0% | 0% | 27 | 55% | 16% | 14% | 24% | ||||||||||||||||
31 | 33-45 | 70% | 0% | 0% | 39 | 69% | 20% | 10% | 24% | ||||||||||||||||
32 | 45-57 | 70% | 0% | 86% | 51 | 78% | 3% | 1% | 24% | ||||||||||||||||
33 | 57-60 | 70% | 0% | 86% | 58.5 | 82% | 4% | 1% | 6% | ||||||||||||||||
34 | Average chance, if susceptible, of catching measles before reaching age 5: | 53.14% | |||||||||||||||||||||||
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36 | To what extent does an SIA reduce the chance of death from measles of a child under 5? | ||||||||||||||||||||||||
37 | Average susceptibility to measles before the SIA: | 10.65% | |||||||||||||||||||||||
38 | Chance (per person) of death from measles before the SIA: | 0.17% | |||||||||||||||||||||||
39 | Average susceptibility to measles after the SIA: | 1.54% | |||||||||||||||||||||||
40 | Chance (per person) of death from measles after the SIA: | 0.02% | |||||||||||||||||||||||
41 | Difference in chance of death due to SIA: | 0.15% | |||||||||||||||||||||||
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43 | 3. Conclusions | ||||||||||||||||||||||||
44 | Cost per life saved: | $1,859.28 | Cost per child under 5 targeted divided by the difference in individual chance of death for a child under 5. | ||||||||||||||||||||||
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46 | Value assigned to averting the death of an individual under 5 due to measles | 120 | |||||||||||||||||||||||
47 | Total units of value generated with hypothetical donation ($100,000) | 6,454.12 | |||||||||||||||||||||||
48 | Total units of value generated with hypothetical donation ($100,000) to GiveDirectly (unconditional cash transfers) | 344 | |||||||||||||||||||||||
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50 | Supplementary immunization activities to prevent measles vs cash | 18.76 | |||||||||||||||||||||||
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