Safety and clinical efficacy of human rabies immunoglobulin in post exposure prophylaxis for category III animal exposures.

The human rabies immunoglobulin (HRIG) is a life-saving immune biological essential for all category III animal exposures. It provides neutralizing antibodies at the site of exposure until the body can produce vaccine-mediated antibodies. We conducted this study to determine the safety and clinical efficacy of an HRIG being used presently for post-exposure prophylaxis (PEP) and to strengthen the existing evidence for its further usage. We conducted a prospective cohort study in 123 subjects with category III animal exposures at the KIMS Hospital and Research Center, Bangalore, India. Post-exposure prophylaxis (PEP) with wound toilet, a single application of HRIG, and a full course of anti-rabies vaccination were provided to all the study subjects. The volume of HRIG was calculated according to the body weight, and all the wounds were infiltrated as was anatomically feasible. All the study subjects were followed up for immediate and delayed adverse events (AE), both local and systemic. Subsequently, all the subjects were followed up for 6 months to demonstrate the clinical efficacy of PEP. The incidence of AEs was 11.4% including local pain, erythema, itching, headache, body ache, fever, and malaise. All AEs were mild and subsided without any complications. All the study subjects were healthy and alive after 6 months following the administration of HRIG, along with a full course of anti-rabies vaccine. Our study provides evidence of safety and clinical efficacy of HRIG for category III animal exposures and supports its continued usage.

Defining the volume of rabies immunoglobulins/ rabies monoclonal antibodies requirement for wound infiltration of category III animal exposures - an exploratory study.

WHO recommends infiltration of rabies immunoglobulins/rabies monoclonal antibodies as anatomically possible, into or close to all category III animal bite wound(s)/exposures for post exposure prophylaxis. The volume required for wound infiltration depending upon the site/size/severity of wound is yet to be defined for guiding the treating physicians. This study aimed to determine the volume of rabies immunoglobulin/rabies monoclonal antibody required for wound infiltration depending upon the site, size, and severity. A prospective cohort study was conducted including category III animal exposures at the anti-rabies clinic, KIMS hospital and Research Center, Bangalore, India. The volume of rabies immunoglobulins/rabies monoclonal antibodies required for wound infiltration, depending on site, severity, and size was determined. All the subjects were followed for 6 months to demonstrate the safety and clinical efficacy of post exposure prophylaxis. The present study included 717 subjects having 1428 bite wounds. There was a significant difference in the median volume required for wound infiltration based on site, size, and severity of bite wounds. However, on pairwise comparison; the median volume among all the pairs for only wound size was found to be statistically significant. Supportively, a strong positive correlation was seen with the size of wound and volume infiltrated. The volume of rabies immunoglobulin/rabies monoclonal antibodies required for wound infiltration shall be determined according to size of wounds, i.e. 1 ml for <1 cm wound, 3 ml for 1-5 cm wound, and 5 ml for >5 cm wound.