Table 1 Comparison of two models in terms of characteristics and parameters used
From: Comparison of LiSTmeasles mortality model and WHO/IVB measles model
| 听 | WHO/IVB | LiST |
|---|---|---|
Model | Natural history model | Cohort model |
Population | 6month to 59 months, UN Population Division projection, revision 2008 | 6month to 59 months, UN Population Division projection, revision 2008 |
Coverage of measles vaccination | MCV1, MCV2 and SIAs [WHO/UNICEF vaccine coverage estimates] | MCV1, MCV2 and SIAs [WHO/UNICEF vaccine coverage estimates] |
Protective effect of SIAs | Account for SIAs in the target and the past 4 years Weighting factor: 100%, 90%, 80%, 50%, and 25% | Account for SIAs in the target and the past 4 years Weighting factor: 100%, 88%, 64.7%, 41.2%, and 17.6% |
Assumption of independence on vaccine receipt | Assume children receive all three doses independently | Assume children receive the second routine dose on top of receiving the first one. Assume receiving routine doses is independent from receiving SIAs |
Coverage being able to distinguish for different age group | Model could be modified to account for that if country-specific information is available | Yes, if country-specific information is available |
U5MR | Not applicable | LiST model uses it for computing number of death [UN estimates] |
Vaccine Effectiveness | 85% for dose 1, 95% for dose 2 and SIAs | 85% for receiving MCV1 only, 94.2% for receiving SIA only and 98% for receiving more than 1 doses |
Herd effect | Not applicable | Herd effect (HE) kicked in when proportion of population protected by MCV reached 90%. Twenty percent HE was added with 1% increment of protection proportion over 90%. HE reached 100% at 95% of the population directly protected by the vaccine, and all children who do not receive MCV would be protected. |
Considering other cause of death | Not applicable | Yes Country-specific cause-of-death profile |
Considering other intervention associated with measles infection or mortality | Not applicable | Yes Stunting, wasting, and vitamin A supplement |
Country-specific CFRs / CFRs multiplication factor | Yes Age-specific CFR, but the value could not adjust the value with availability of treatments or other intervention | Not applicable |
Age-specific case distribution | Yes Different age distribution of cases owing to measles coverage higher or lower than 80% | Not applicable |