A team of researchers in the United States has produced antibodies to the SARS-CoV-2 spike protein using hen eggs.
Antibodies derived from eggs could be used to treat Covid-19 or as a preventative measure for people exposed to the disease, according to researchers in the journal Viruses.
Birds produce IgY antibodies, which are similar to IgG antibodies found in humans and other mammals. IgY, which does not cause allergy or immune reactions in humans when injected, is found in both the sera and the eggs of birds.
According to researchers from the University of California-Davis, a hen can produce a lot of IgY because she lays about 300 eggs per year.
“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 researchers administered two doses of three different vaccines based on the SARS-CoV-2 spike protein or receptor binding domain to hens.
Three and six weeks after the last immunisation, they measured antibodies in hen blood samples and egg yolks.
The ability of purified antibodies to prevent coronavirus infection of human cells was tested.
SARS-CoV-2 antibodies were found in both eggs and sera from immunised hens. Serum antibodies were more effective at neutralising the virus, probably because there is more antibody in blood overall, according to Gallardo.
Gallardo is developing the egg-based antibody technology with colleagues at Stanford University and the University of Technology, Sydney. The researchers hope to use these antibodies in a preventative treatment, such as a spray, that people at high risk of coronavirus exposure can use.
