Promising Mini Antibodies Against COVID-19 Isolated

Investigators at the National Institutes of Health (NIH) have discovered a set of small antibodies that were produced by a llama which look promising to fight against the coronavirus disease 2019 (COVID-19). The study, published in Scientific Reports, suggests that one of the isolated nanobodies, NIH-CoVnb-112, has the potential to detect virus particles and prevent infections. It was also found that the antibody worked just as well in liquid or aerosol form, showing the possibility of it being effective through inhalation.

"For years…I had been testing out how to use nanobodies to improve brain imaging. When the pandemic broke, we thought this was a once in a lifetime, all-hands-on-deck situation and joined the fight," David L. Brody, senior author of the study said. "We hope that these anti-COVID-19 nanobodies may be highly effective and versatile in combating the coronavirus pandemic."

Nanobodies are a type of antibody that are naturally produced by camelids immune systems, which are the group of animals that include llamas, alpacas and camels. When these nanobodies are isolated in a lab, they weigh about the tenth of the weight of a human antibody. Due to the fact that they are less expensive to produce, while also being more stable, they are easier to engineer, making them excellent for medical research.

Investigators immunized the llama 5 times over the course of 28 days in order to isolate the nanobodies responsible for blocking infections. They then covered the virus spike proteins teeth with the antibody, stopping the virus from binding to the ACE2 receptor. They discovered 13 nanobodies that may do this, but found that NIH-CoVnb-112 was the strongest one. They also showed that NIH-CoVnb-112 could be effective at preventing COVID-19 infections by genetically mutating a harmless pseudovirus, which the antibodies prevented from infecting cells.

"Although we have a lot more work ahead of us, these results represent a promising first step,” Thomas J. Esparza, co-author on the study said. "With support from the NIH we are quickly moving forward to test whether these nanobodies could be safe and effective preventative treatments for COVID-19. Collaborators are also working to find out whether they could be used for inexpensive and accurate testing."