- Documented negative serologic testing for human immunodeficiency virus (HIV), hepatitis B (unless serologically positive due to prior vaccination), and hepatitis C within the year prior to enrollment (note: for guidance in defining active infection for hepatitis B, please refer to the WHO guidelines. (World Health Organization, Global Alert and Response (GAR), Hepatitis B (who.int/csr/disease/hepatitis/ whocdscsrlyo20022/en/index4.html)