  Because a fast vaccination rollout against coronavirus disease 2019
(COVID-19) is critical to restore daily life and avoid virus mutations, it is
tempting to have a relaxed vaccination-administration management system.
However, a robust management system can support the enforcement of preventive
measures, and in turn, reduce incidence and deaths. Here, we model a trustable
and reliable management system based on blockchain for vaccine distribution by
extending the Susceptible-Exposed-Infected-Recovery (SEIR) model. The model
includes prevention measures such as mask-wearing, social distance, vaccination
rate, and vaccination efficiency. It also considers negative social behavior,
such as violations of social distance and attempts of using illegitimate
vaccination proofs. By evaluating the model, we show that the proposed system
can reduce up to 2.5 million cases and half a million deaths in the most
demanding scenarios.
