Abstract: Methods for producing mono-specific immunoglobin Y (IgY) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are disclosed. IgY antibodies are found in birds and can be isolated from egg yolk of chicken eggs. Hens are immunized with a SARS-CoV-2 spike protein comprising an ACE2 receptor binding domain (RBD). IgY antibodies against the RBD are isolated from eggs laid by the hens. The isolated RBD-IgY antibodies were tested in vitro in mammalian cells, wherein the RBD-IgY blocked SARS-CoV-2 infection of the cells. A pharmaceutical composition comprising the mono-specific IgY antibodies can be used to inhibit or treat COOVID-19, the SARS-CoV-2 infection. IgY antibodies are generally regarded as safe and offer various production and treatment advantages when compared to mammalian antibodies.

Abstract: Chicken egg yolk antibodies (IgY Abs) specific to the Middle Eastern Respiratory Syndrome coronavirus spike (MERS-CoV S) protein demonstrate efficacy against MERS-CoV infection. The S-specific IgY Abs (anti-S IgY) are produced by injecting chickens with purified a recombinant MERS-CoV S protein, S1 subunit, or an S1 fragment. The purified anti-S IgY specifically bind to the MERS-CoV S protein and inhibit infection. In vitro neutralization of the IgY Abs against MERS-CoV was achieved in cell lines and in a human-transgenic mouse model treated with a pharmaceutical composition comprising the anti-S IgY. Viral antigen-positive cells in treated mice were reduced, compared to the adjuvant-only controls. Moreover, lung cells of anti-S IgY-treated mice showed significantly reduced inflammation, compared to the controls. Efficient neutralization of MERS-CoV infection is demonstrated both in vitro and in vivo using the anti-S IgY Abs.