Vaccination strategies determine who gets vaccinated when supply is limited.
Strategy Types
- Mass: Vaccinate everyone systematically
- Ring: Vaccinate contacts of cases
- Targeted: Prioritize high-risk groups
- Random: No prioritization
Trade-offs
- Ring vaccination works well for slow diseases
- Targeted reaches vulnerable but may miss spreaders
- Mass is equitable but may be slow
Herd Immunity
Need to vaccinate 1 - 1/R₀ of population. For R₀ = 3, that's 67%.