New York: A team of researchers in the US has produced antibodies to the SARS-CoV-2 spike protein in hen eggs.
Antibodies harvested from eggs might be used to treat Covid-19 or as a preventative measure for people exposed to the disease, said researchers in the paper published in the journal Viruses.
Birds produce a type of antibody called IgY, comparable to IgG in humans and other mammals. IgY, which does not cause allergy or set off immune reactions when injected into humans, appears both in birds’ sera and in their eggs.
As a hen lays about 300 eggs a year, you can get a lot of IgY, said researchers from the University of California-Davis.
“In addition to a low cost to produce these antibodies in hens, they can be updated very fast by using updated antigens to hyperimmunised hens, allowing protection against current variant strains,” said Rodrigo Gallardo, Professor in poultry medicine, Department of Population Health and Reproduction at the UC Davis School of Veterinary Medicine.
The team immunised hens with two doses of three different vaccines based on the SARS-CoV-2 spike protein or receptor binding domain.
They measured antibodies in blood samples from the hens and in egg yolks three and six weeks after the last immunisation.
Purified antibodies were tested for their ability to block coronavirus from infecting human cells.
Both eggs and sera from immunised hens contained antibodies that recognised SARS-CoV-2. Antibodies from serum were more effective in neutralising the virus, probably because there is more antibody in blood overall, Gallardo said.
Gallardo is working with colleagues at Stanford University and University of Technology, Sydney, to develop the egg-based antibody technology. The team hopes to deploy these antibodies in a preventative treatment such as a spray, that could be used by people at high risk of exposure to coronavirus.