  Understanding how the network topology affects the spread of an epidemic is a
main concern in order to develop efficient immunization strategies. While there
is a great deal of work dealing with the macroscopic topological properties of
the networks, few studies have been devoted to the influence of the community
structure. Furthermore, while in many real-world networks communities may
overlap, in these studies non-overlapping community structures are considered.
In order to gain insight about the influence of the overlapping nodes in the
epidemic process we conduct an empirical evaluation of basic deterministic
immunization strategies based on the overlapping nodes. Using the classical SIR
model on a real-world network with ground truth overlapping community structure
we analyse how immunization based on the membership number of overlapping nodes
(which is the number of communities the node belongs to) affect the largest
connected component size. Comparison with random immunization strategies
designed for networks with non-overlapping community structure show that
overlapping nodes play a major role in the epidemic process.
