How Online Social Ties Influence the Epidemic Spreading of a Multiplex Network

In recent years, many studies have focused on the interrelation between the epidemic spreading and the spread of awareness to prevent infections. A multiplex network is utilized to depict this scenario. The upper layer of the multiplex network represents an online social network, where the awareness of epidemic spreads. The lower layer of the multiplex network represents an off-line social network, where the epidemic spreads among individuals. However, most previous studies neglected that the online social network has diverse social ties, such as the dense social ties (in-roles and friends) and the sparse social ties (familiar strangers and strangers). In this work, we study how the online social ties impact on epidemic spreading in the off-line social network. We assume that besides the same dense in-roles and friends, an online social network could have only familiar strangers, only strangers, or both. We analyze the influence of the effective epidemic spreading rate and the awareness spreading rate on the infection fraction at the steady state with two empirical datasets. An interesting finding is that an online social network containing strangers is more likely to reduce epidemic prevalence than that containing familiar strangers.