  A new method (`explosive immunization' (EI)) is proposed for immunization and
targeted destruction of networks. It combines the explosive percolation (EP)
paradigm with the idea of maintaining a fragmented distribution of clusters.
The ability of each node to block the spread of an infection (or to prevent the
existence of a large cluster of connected nodes) is estimated by a score. The
algorithm proceeds by first identifying low score nodes that should not be
vaccinated/destroyed, analogously to the links selected in EP if they do not
lead to large clusters. As in EP, this is done by selecting the worst node
(weakest blocker) from a finite set of randomly chosen `candidates'. Tests on
several real-world and model networks suggest that the method is more efficient
and faster than any existing immunization strategy. Due to the latter property
it can deal with very large networks.
