In lab mice, bioengineered cows that produce large quantities of human polyclonal antibodies have effectively neutralized MERS-CoV and prevented infection in a study.
The researchers used SAB301 to vaccinate two groups of cows whose immunoglobulin (Ig) genes – which produce antibodies – have been replaced with an artificial chromosome carrying the human Ig genes. When vaccinated, these cows develop a robust immune response, and produce fully human polyclonal antibodies against MERS-CoV.
Gabriel DeFang and his colleagues then purified the antibodies from the cows’ blood, and tested them to evaluate their efficacy. They found that SAB301 effectively eliminated MERS-CoV from infected cells grown in Petri dishes, and that a single dose of it, administered to mice either 12 hours before or 24 and 48 hours after MERS-CoV infection, protected the animals from the virus.
The bioengineered cows used in the study produced between 150 – 600g of the antibodies per month, so the results, which have just been published in the journal Science Translational Medicine, suggest that this approach could offer a valuable new platform for the mass production of treatments for MERS-CoV and other emerging infectious diseases.
Kanakatte Raviprakash of the Naval Medical Research Center in Silver Spring, Maryland, a co-author of the study, says the next step is to file an application with the US Food and Drug Administration to start phase I studies in humans. “Availability depends upon many factors including the results of Phase II/III efficacy trials. We hope that if safety and efficacy is proven, then sufficient therapeutic would be available to those in need of treatment.”