30% of 6M or 1.8M new cases per year would be prevented by the vaccine once released.
6000000 * 0.3 = 1800000

The grant would accelerate vaccine release by 3 years, meaning 5.4M cases would be prevented if the grant succeeds.
3 * 1800000 = 5400000

Assuming the proportion of lost DALYs to new cases is consistent, 1/6M would be the same proportion as 0.9/5.4M.
(1 ÷ 6000000) * 5400000 = 0.9

2.7 DALYs lost over the three-year difference if the grant is successful.
20 - 17 = 3
3 * 0.9 = 2.7

If grant fails: value of DALYs lost is $1M. If grant succeeds: value of DALYs lost is $985 000. The grant would recover $15 000 in lost DALYs if successful.
20 * 50000 = 1000000
(17 * 50000) + (2.7 * 50000) = 985000

95% chance the grant fails, 5% chance the grant succeeds.
1000000 * 0.95 = 950000
985000 * 0.05 = 49250
950000 + 49250 = 999250
1000000 - 999250 = 750

The social ROI on the grant would then be $750 divided by the original $5M dollar investment, or 0.00015x.
750 ÷ 5000000 = 0.00015

Edit
Pub: Aug 01 2021 09:17 UTC
Edit: Aug 01 2021 09:17 UTC
Views: 31