The researchers of this study performed a clinical research to evaluate the safety and potential efficacy of a new human rabies immune globulin (KEDRAB) vs an older product, as well as to see if HRIG interferes with the formation of endogenous antibodies versus Comparator when administered with an active rabies vaccination. This was a single-period, prospective, double-blind, non-inferiority research in which patients were randomly assigned to a single dose of HRIG or Comparator on day 0 and rabies vaccination on days 0, 3, 7, 14, and 28. On day 14, anti-rabies antibodies were assessed using a fast fluorescent focus inhibition test, and patients were tracked until day 185. Titers of 0.5 IU/mL of rabies virus neutralizing antibody (RVNA) were deemed seroconversion and potentially protective. On day 14, 98.3% of the 59 patients in the HRIG group and 100% of the 59 subjects in the Comparator group had RVNA 0.5 IU/mL. One patient in the HRIG group did not satisfy the seroconversion requirements for anti-rabies antibody, while one person in the Comparator group had an anamnestic reaction, with much higher than anticipated anti-rabies antibody levels at both baseline and day 14.
Thus, when combined with rabies vaccination, HRIG allows for preventive anti-rabies antibody titers and is non-inferior to Comparator.
Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2019.1656967
