Simulating rabies post-exposure prophylaxis among patients with human immunodeficiency virus infection using a six-dose Essen regimen administrated with human diploid cell vaccine: A single-arm pilot study in Chinese population

To explore the immunogencity and safety of HDCV using a six-dose Essen regimen in human immunodeficiency virus (HIV) infected patients. We conducted a single-arm pilot study by simulating post-exposure prophylaxis (PEP) in HIV-infected patients. All patients were administrated with HDCV using a 6-dose Essen regimen (consisting of 2 doses on day 0, and 4 doses each on day 3, 7, 14, and 28). Rabies virus-neutralizing antibody (RVNA) titers were detected on day 0, 7, 14, and 45, separately. The adverse reactions were also observed. In addition, we divided the patients with the baseline CD4+ T-cell counts of 500 cells/μL to examine the correlation between primary CD4+ T-cell counts and RVNA titers among HIV patients. Thirty patients included in the study were mostly male (96.7%), with a median age of 30.5 years and stable antiretroviral therapy (ART) treatment. Patients had RVNA titers of 0.84 IU/mL on day 7, 9.94 IU/mL on day 14, and 4.02 IU/mL on day 45 after vaccination, with significant differences between day 7 and day 14. The seroconversion rate reached 100% on day 14. Only three patients developed transient adverse reactions（including fever and redness, swelling, pain, and induration at the injection site）. There was no significant difference in antibody titers and safety profile between patients with CD4+T-cell counts below and above 500 cells/μL. A favorable immune response was achieved in HIV patients using the six-dose Essen regimen with HDCV. The safety profile of HDCV is satisfactory, with no major adverse events.