How Llama Antibodies Could Be Used As a New COVID Treatment

Scientists have found that a unique type of antibody produced by llamas can effectively target the SARS-CoV-2 virus, which causes COVID-19.

The authors of a study documenting the findings, which were published in the journal Nature Communications, said the research could lead to the development of new frontline treatments against the disease that can be administered in the form of a simple nasal spray.

An international team of researchers, led by scientists from the U.K. government-supported Rosalind Franklin Institute in England, found that short chains of molecules known as nanobodies effectively neutralized the SARS-CoV-2 virus in infected hamsters, which were being used as a model for the human immune system.

The nanobodies—a smaller, simple form of antibody produced by the immune systems of llamas and camels—significantly reduced signs of the disease in the infected hamsters.

The research team were able to generate four types of nanobody chains by injecting the spike protein of the SARS-CoV-2, which the virus uses to bind to human cells, into a llama called Fifi at the University of Reading in the U.K.

This did not make the animal sick, but Fifi's immune system responded to fight off the pathogen, generating nanobodies in the process.

The scientists then took a blood sample from the llama, extracting four nanobody chains that they then used in their experiments.

According to the paper, three of the nanobodies were capable of neutralizing both the original variants of the SARS-CoV-2 virus and the Alpha variant first identified in the U.K. A fourth nanobody chain was found to be effective at neutralizing the Beta variant, which was first detected in South Africa.

Public Health England—a U.K. government agency that provided researchers for the study—said in a statement that the latest findings have "significant potential for both the prevention and treatment of COVID-19."

Nanobodies "are among the most effective SARS-CoV-2 neutralizing agents we have ever tested," the agency said.

The authors of the study said nanobodies could provide a cheaper and easier alternative to treating people with human antibodies collected from patients who have already recovered from COVID-19.

Human antibody treatments have played an important role over the course of the pandemic, but they typically need to be administered via infusion through a needle in a hospital, limiting their use.

While the latest research is still at an early stage, researchers say it could pave the way for the development of new effective treatments against COVID-19.

In addition, nanobodies can be produced in large quantities in the lab and don't need to be kept in cold storage.

Ray Owens, a professor at the Rosalind Franklin Institute who led the research, said in the statement: "Nanobodies have a number of advantages over human antibodies.

"They are cheaper to produce and can be delivered directly to the airways through a nebuliser or nasal spray, so can be self-administered at home rather than needing an injection. This could have benefits in terms of ease of use by patients but it also gets the treatment directly to the site of infection in the respiratory tract."

Several experts have said developing new treatments will be crucial as the pandemic continues, particularly for populations that haven't been vaccinated, or for individuals who do not respond to vaccines.

Professor James Stewart, co-author and professor of molecular virology at the University of Liverpool said in the statement: "The pre-clinical trials of the nanobodies in hamsters are extremely encouraging and suggest that they may be effective at treating COVID-19 disease as well as help prevent infection.

"Having therapies such as this will be important for populations that are either unvaccinated or where vaccination is inappropriate or ineffective."