Scientists around the globe are exploring ways to fight COVID-19 as we self-quarantine and wait. Though a potential treatment for COVID-19 may not be the first thought that comes to mind when you hear your kids watching episodes of “Llama Llama” on Netflix during your Monday morning conference call, llamas may be part of our ticket back to normalcy.
A New Study Finds Possible Therapeutic Uses for Llama Antibodies in Treatment of COVID-19
Perhaps it was serendipity?
Researchers from the University of Texas, in collaboration with Ghent University in Belgium, had been exploring how proteins from the viruses that caused MERS and SARS functioned using a llama named Winter when COVID-19 struck.
When COVID-19 hit, they decided to see if any of the nanobodies they harvested from Winter could stop SARS-CoV-2 from infecting cells. SARS-CoV-2 is the strain of coronavirus responsible for the current pandemic.
The team published their results in Cell last month.
Llama Nanobodies to the Rescue
The researchers injected a llama with prefusion-stabilized MERS-CoV and SARS-CoV-1 spikes. Spike proteins are the proteins on the surface of coronaviruses. They undergo a structural change after attaching to cells that allow the virus to fuse with the host cell, enter it, and copy itself to produce more viruses. Nanobodies harvested from llamas are a possible way to prevent the virus from entering cells because they bind to spike proteins.
The SARS VVH-72 nanobody was one of a handful of nanobodies harvested to target SARS and MERS, that also bound spike proteins on SARS-CoV-2, albeit not long enough to be effective.
The researchers fused two copies of SARS VVH-72 to improve its binding capacity. This engineered version prevented SARS-CoV-2 from entering cells.
SARS VVH-72 is among the first antibodies known to neutralize the strain of the virus responsible for COVID-19.
According to the authors of the study, its biophysical properties and robust neutralization capacity render it ideal for further testing in the development of COVID-19 treatments.
Implications for Humans
While a vaccine will likely come along in the next one to two years, there will still be a need for nonvaccine treatments, and that is where the results of this study come into play.
For example, vaccines will not help an infected person, but antibody injections could bolster the infected person's immune response. Likewise, vaccines are not always enough. People who struggle to develop a sufficient immune response to vaccines would probably benefit from antibody therapy.
Llama antibodies may be a possible treatment for COVID-19, but not as a vaccine. Instead of injecting patients with something that produces an antibody response as is the case with vaccines, doctors and nurses would administer the actual antibodies directly to patients, possibly using an inhaler.
Either way, an antibody treatment is still at least a year off if all the research trials involved in developing this treatment are successful.
Why Llamas?
Llama antibodies are approximately one-quarter of the size of a typical human antibody and can be cloned with relative ease to form smaller antibodies known as nanobodies. Nanobodies are attractive because they are easy to mass-produce, and their properties make them effective weapons for boosting immune responses to specific pathogens.
Alpacas, camels, and sharks are also appealing to researchers for similar reasons.
No Harm to Llama
No harm came to Winter the Llama. Winter was injected with a noninfectious segment of the virus to generate an antibody response.
