Persons may catch a virus.Logical formLearned from37 sentences. Exposure can be to a virus.Logical formLearned from37 sentences. A virus may reactivate.Logical formLearned from36 sentences. A virus may be involved.Logical formLearned from36 sentences. Viruses may undergo a creation.Logical formLearned from36 sentences. A virus can be fatal.Logical formLearned from36 sentences. A vaccine can be against a virus.Logical formLearned from36 sentences. Patients may be infected with virus.Logical formLearned from36 sentences. Persons may die from a virus.Logical formLearned from36 sentences. Forms may pertain-to a virus.Logical formLearned from36 sentences. A virus may cause an illness.Logical formLearned from36 sentences. A virus may scan.Logical formLearned from36 sentences. A (bird flu virus) can be lethal.Logical formLearned from36 sentences. A virus may pertain-to a company.Logical formLearned from36 sentences. A (bird flu virus) may remain hard.Logical formLearned from36 sentences.