- Acute disease within 72 hours prior to vaccinations, defined as the presence of a moderate or severe illness (as determined by the investigator through medical history and physical examination; for example, those requiring an absence from work) with or without fever, or a fever >37.9ºC orally. Study vaccine can be administered to persons with a minor illness, such as diarrhea, or mild upper respiratory tract infection with or without low-grade febrile illness. Vaccination can be delayed until the subject has recovered.