SARS-CoV-2-specific immunoglobulin Y antibodies are protective in infected mice

• Published in: PLoS pathogens 2022-09, Vol.18 (9), p.e1010782
• Main Authors: El-Kafrawy, Sherif A, Odle, Abby, Abbas, Aymn T, Hassan, Ahmed M, Abdel-Dayem, Umama A, Qureshi, Arooj K, Wong, Lok-Yin Roy, Zheng, Jian, Meyerholz, David K, Perlman, Stanley, Zumla, Alimuddin, Azhar, Esam I
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Antibodies, Viral; Antigens; Antiviral activity; Antiviral Agents; Biology and Life Sciences; Chickens; Coronaviruses; COVID-19 - prevention & control; COVID-19 vaccines; Edema; Effectiveness; Eggs; Evaluation; FDA approval; Female; Gel electrophoresis; Health aspects; Hemorrhage; Humans; Immunization; Immunization (passive); Immunoglobulin Y; Immunoglobulins; Inflammation; Intranasal administration; Laboratories; Medicine and Health Sciences; Mice; Molecular weight; Morbidity; Neutralization; Polyethylene glycol; Proteins; Research and Analysis Methods; Respiratory diseases; SARS-CoV-2; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Sodium lauryl sulfate; Testing; Viral diseases; Viruses; Yolk
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1010782

Safe, passive immunization methods are required against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its variants. Immunization of chickens with antigen is known to induce specific IgY antibodies concentrated in the egg yolk and has a good safety profile, high yield of IgY per egg, can be topically applied, not requiring parenteral delivery. Our data provide the first evidence of the prophylactic efficacy of Immunoglobulin Y antibodies against SARS-CoV-2 in mice. Lohmann hens were injected with recombinant SARS-CoV-2 RBD protein; IgY-Abs were extracted from the eggs and characterized using SDS-PAGE. Antiviral activity was evaluated using plaque reduction neutralization tests. In additional experiments, IgY-RBD efficacy was examined in mice sensitized to SARS-CoV-2 infection by transduction with Ad5-hACE2 (mild disease) or by using mouse-adapted virus (severe disease). In both cases, prophylactic intranasal administration of IgY-Abs reduced SARS-CoV-2 replication, and reduced morbidity, inflammatory cell infiltration, hemorrhage, and edema in the lungs and increased survival compared to control groups that received non-specific IgY-Abs. These results indicate that further evaluation of IgY-RBD antibodies in humans is warranted.