Figure 4. Relative risks of extinction on an island.

The probability of extinction for island countries divided by the probability of extinction for non-island countries for 4 childhood infections relative to extinction on the mainland; showing only a fraction of the distribution for mumps for clarity. The proportion of migrants and HDI are set to the median across all countries (–3.52 and 0.67 respectively), and the population size of unvaccinated children is set to 1e5. Median values are 1.92 (1.04–3.37) for rubella, 1.51 (1.07–2.16) for measles, 10.26 (4.06–25.29) for mumps, and 2.27 (1.57,3.32) for pertussis; brackets indicate 2.5% and 97.5% quantiles from prediction made across 2000 samples from the estimated multivariate normal distribution of the parameters.