Fig. 1

Summary of the mathematical model used to quantify inequalities between social groups H (high risk) and L (low risk). a The epidemiological model, where S_i,G, E_i,G, I_i,G. R_i,G and λ_i,G are the proportion susceptible, infected but not infectious, infectious, recovered and force of infection in age group i and social group G (either group H or group L), ρ is the proportion vaccinated, σ is the rate at which infected individuals become infectious and γ is the rate of recovery from infection. Population also moves out of these groups into other age groups and are removed when they die (not shown in this schematic). b A schematic of the population model with higher contact rate in group H than group L; the groups also differ in susceptibility (not shown). c An example transmission matrix, showing the relative transmission rate between age and social groups with all social mixing and susceptibility assumptions included with parameterisation χ = 0.6, η = 0.6, ξ = 0.05 (rates normalised such that the highest transmission group 10–14 years old in group H has a rate of 1. The same age group has a rate of 0.36 within group L (low susceptibility and reduced contact rate, χ and η), 0.05 from group L to group H (between-group contact rate, ξ) and 0.03 from group H to group L (between-group contact rate and reduced susceptibility, ξ and η)