In generating the infection networks, we set L = 50 as the maximum number of friends a node can have. To produce high clustering coefficients, we ensure that the mutual friend formation is dominant over the random friend formation by choosing n m = 400 and n r = 100. For simplicity, we choose r = n r +n m = 500 such that the total number of links (hence the average degree ,k.) of the initial random network remains more or less constant. This way, we can generate social-like infection networks with arbitrary size and average degree by simply adjusting N and ,k. of the initial random network to the desired values.