A Low-Cost COVID-19 Treatment, Made in Horses

WRITTEN BY: Tara Fernandes

Researchers in Costa Rica are turning to horses as an unlikely source of potential therapeutic antibodies against COVID-19. If these equine immunoglobulins prove to be effective in humans, they could fill a desperately needed gap in accessible pharmaceuticals to help patients with severe, life-threatening cases of COVID-19. Critically, horse antibodies would be significantly cheaper to mass-produce than human antibodies.

So far, preliminary studies in the lab show that the horse antibodies against SARS-CoV-2 were able to kill the virus. The Clodomiro Picado Institute first started using horses to create antibodies as antidotes to venomous snake and spider bites. Horses are exposed to minute amounts of these venoms and over time, build up resistance to them by generating venom-targeting antibodies. Equine antivenoms manufactured at the institute save the lives of over 500 people in Costa Rica annually, and thousands more in other countries.

The team is now channeling their expertise in equine immunology into generating COVID-19 treatments, by swapping venom injections for the spike protein of SARS-CoV-2. This work has been spurred by previous successes in generating antibodies against other pathogenic viruses such as influenza and a related coronavirus that causes the Middle East Respiratory Syndrome, or MERS.

Alape Girón, lead researcher of the COVID-19 project said, “The idea behind the antibody therapy for patients with COVID-19 is similar to that of treating patients suffering from snakebite poisoning.”

“We want to generate specific antibodies against viral structures in horses, purify the antibodies and give them to patients who are starting to fight the infection but whose immune system still does not produce enough antibodies to clear the viral particles, ” he explained.

The next steps for the team include an accelerated clinical trial to test their efficacy in 26 COVID patients, scheduled to commence shortly. Should the results turn out to be promising, more comprehensive clinical studies involving larger cohorts will be conducted. A single vial of horse antibodies, which target multiple sites on the coronavirus, will cost an estimated $100 to manufacture, around ten-fold cheaper than what it costs to make a human monoclonal equivalent.