Figure 3.

Rationalising the enlightened self-interest incentive mechanism. Panel A. Illustration of the incentive mechanism behind the enlightened self-interest guided vaccine sharing strategies. By categorising the infection into local infections (orange area) and imported infections (blue area), we expect under more active vaccine sharing strategies, there will be a net reduction in infections (deep blue line), although the local infections may increase (red line), due to the reduced imported infections. Panel B. Marginal utility of vaccines based on real-world vaccine distribution. It demonstrates that the effectiveness of extra vaccines vanishes in regions with high vaccination rates, such as NAC and ECS. The error bar demonstrates 95% of confidence intervals. Panel C. Flow of reduced infection cases under the enlightened self-interest guided vaccine sharing strategy, started from 90% vaccination with 90% vaccines shared, comparing with the selfish strategy. Panel D. Quantifying the disentangled imported transmission and local transmission. For group 1, they have reduced local transmission due to vaccine sharing. For group 2, both the imported transmission and local transmission will reduce. For group 2, the received imported transmission benefit outweighs the increasing of local transmission. The shaded area represents the standard deviation.