Evaluation of one year immunity following rabies post-exposure prophylaxis in dog bite cases
Nisa Ya, Heidi Auerswald, Sothy Touch, Saraden In, Chanvannak Yun, Pisey Thai, Sotheary Sann, Borita Heng, Chanthy Leng, Veasna Duong, Yik Sing Peng, Sowath Ly, Tineke Cantaert
Abstract
Rabies remains a global health threat despite being preventable with post-exposure prophylaxis (PEP). This study assessed one-year humoral and T cell immunity in PEP recipients of the Insitut Pasteur du Cambodge (IPC) regimen, recommended by WHO. We analyzed rabies virus (RABV) neutralizing antibodies (nAbs) and T cell responses at baseline, 7 and 14 days, 6 and 12 months after PEP. A total of 148 patients were included, with 78 bitten by confirmed RABV-positive dogs receiving PEP and equine rabies immunoglobulins (eRIG), and 70 bitten by RABV-negative dogs receiving only PEP. Fourteen days after PEP, all but two individuals seroconverted for nAbs ( ≥ 0.5 IU/mL) with 87% maintaining this response even after 12 months. Interleukin-4 (IL-4) and interferon-gamma (IFN-γ)-secreting T cells were significantly elevated after 14 days and sustained for one year. No differences were observed between the RABV-exposed and -unexposed groups. This study demonstrates robust one-year immunity after IPC PEP.