Problem
The key is that you evaluate equity and vaccination to estimate the number of lives that could be saved if effective coverage in the poorest quintile is equal to effective coverage in the wealthiest quintile.
Describe a vaccination program (routine immunization, pneumococcal, etc) in Nigeria. Those data are available through DHS and MICS. If there is an equity gap in vaccination coverage, how many people are affected? In other words, estimate the number of deaths from vaccine-preventable diseases that could be prevented if the poorest quintile had the same effective coverage as the wealthiest quintile. What you you think is the most impactful bottleneck to effective coverage in the poorest quintile? Why?