Production and evaluation of rabies immunoglobulin extracted from chicken egg yolk

This study investigated the potential of using laying hens to produce rabies immunoglobulin (RIG) due to concerns about an African Horse Sickness outbreak in 2020. The hens were immunized with rabies vaccine, resulting in the production of Immunoglobulin Y (IgY) antibodies in their egg yolks. The study found that using polyethylene glycol 6000 (PEG) was the most effective method for extracting anti-rabies IgY from egg yolks in terms of amount (1.87 mg of IgY from one mL of egg yolk), purity (83 %), and cost-effectiveness. Further purification through affinity chromatography increased the purity to 95 %, as confirmed by 1D GeLC-MS/MS, showing a purity of up to 98 %. In addition, IgY extracted using PEG demonstrated the highest neutralizing activity compared to the caprylic acid and ammonium sulfate methods. It was estimated that only 8 eggs are needed to produce a vial of RIG with the same potency as equine RIG (1000 IU/vial).