Wang, M., Barasheed, O., Rashid, H., Booy, R., El Bashir, H., Haworth, E., …Heron, L. (in press). A cluster-randomised controlled trial to test the efficacy of facemasks in preventing respiratory viral infection among Hajj pilgrims. Journal of Epidemiology and Global Health, 5(2), https://doi.org/10.1016/j.jegh.2014.08.002