Mutations may aid a virus.Logical formLearned from14 sentences. Viruses may outstrip defenses.Logical formLearned from14 sentences. Some generations may be removed from a virus.Logical formLearned from14 sentences. Some mutations may weaken a virus.Logical formLearned from14 sentences. A (blood level) of a virus may drop.Logical formLearned from14 sentences. A (blood level) may pertain-to a virus.Logical formLearned from14 sentences. A cell may be infected by a kind of virus.Logical formLearned from14 sentences. Some strains of a virus may exist in a person.Logical formLearned from14 sentences. A (virus count) may pertain-to patients.Logical formLearned from14 sentences. A virus may count in (blood rises).Logical formLearned from14 sentences. A virus may pay.Logical formLearned from14 sentences. Patients may harbor strains of a virus.Logical formLearned from14 sentences. A virus can be generations.Logical formLearned from14 sentences. A virus may use at a stage of a (life cycle).Logical formLearned from14 sentences. A cover may pertain-to a virus.Logical formLearned from14 sentences.