tokens: New strategies that attenuate via mechanisms distinct from loss-of-function are needed for enhancing the safety phenotype of viral genome .
folded_tokens: new strategies that attenuate via mechanisms distinct from loss-of-function are needed for enhancing the safety phenotype of viral genome .
labels: O O O O O O O O B-other_name O O O O O O O O B-DNA_family_or_group I-DNA_family_or_group O