It is challenging to improve the performance of WBANs in a mobile social environment due to mobility, privacy concerns, and dynamic social interactions. Mobile social networks are capable of providing an opportunity to address the challenge for rapidly increasing m-Health applications. In this article we propose to construct new algorithms and theoretical models to build s-WBANs that can bridge the WBANs and social networks in the mobile sensing environment. With s-WBANs vital sign data collection and data fusion can be performed reliably and securely over a dynamic social environment. Further, an s-WBAN application of epidemic control by fusing the information of WBANs and social interaction via mobile gateway (i.e. smartphone) will be investigated, illustrating the practical significance of the proposed s-WBANs.