Can live attenuated virus work as post-exposure treatment?

Simple mathematical models for the competition between different virus variants in the presence of a crossreactive immune response show that, contrary to expectation, selection can favour variants that induce low viral loads. Here, Sebastian Bonhoeffer and Martin Nowak suggest that such 'competitively superior', but 'less pathogenic', mutants may be a possibility for post-exposure treatment of persistent virus infections.