MUTATION TOLERANCE ENHANCED. “While the impact of viral recombination in evolution remain somewhat obscure, it is clear that these processes can also repair mutated genomes by purging mutations even in cells infected at low multiplicity. Thus, these “repairs” maintain viral fitness, and they may serve to increase the mutational tolerance of viral populations.”
http://www.sciencedirect.com/science/article/pii/S0042682215001580