In August, the University of California developed AeroNabs, an inhalable substance with promising results as protection against coronavirus. In a recent study, the University of Pittsburgh proposed another treatment that can be developed into inhalable therapeutics.
The findings were recently published in the journal Science. Researchers describe special coronavirus antibody fragments from llamas known as nanobodies.
Llama nanobodies are significantly smaller than human antibodies but are powerful enough to neutralize the virus. The SARS-CoV-2 nanobodies are also more stable and are a cost-effective treatment.
Professor Yi Shi said that nature is indeed the best inventor. The technology the team developed led to the discovery of highly potent neutralizing nanobodies extracted from camelids. They found "thousands of nanobodies with unrivaled affinity and specificity."
Wally the llama was the key to discovering the powerful nanobodies. The team immunized Wally with a fragment of the coronavirus spike protein or a recombinant protein receptor-binding domain (RBD). About two months later, the llama had a robust production of nanobodies against SARS-CoV-2.
Researcher Yufei Xiang identified the nanobodies in Wally's blood that strongly bound with the virus using a mass spectrometry-based technique. The nanobodies were then exposed to the live virus which is effectively neutralized. Xiang not only discovered an effective antibody candidate, but she also identified nanobodies nearly thousands of times more effected than previously identified llama antibodies for former treatments.
Researchers from the Hebrew University of Jerusalem helped identify how the llama antibodies have multiple mechanisms against SARS-CoV-2, making it ideal for bioengineering. For example, the nanobodies can bind to multiple regions of the virus protein. If parts of the virus mutate or become resistant to treatment, the nanobodies can still bind to other parts of the virus.
New Inhalable Treatment
Nanobodies have the potential to be more affordable than the traditional coronavirus antibodies that are administered via IV, which also require a larger dose. Wally's robust nanobodies are "ideal for addressing the urgency and magnitude of the current crisis." Moreover, Wally's nanobodies remain stable at room temperature for six weeks. Developing the llama antibodies into an inhalable mist would be a new antiviral treatment to treat coronavirus.
"As a virologist, it's incredible to see how harnessing the quirkiness of llama antibody generation can be translated into the creation of a potent nanoweapon against clinical isolates of SARS-CoV-2," said Dr. Paul Duprex. Despite multiple companies developing vaccines around the world, they may only be widely available by late next year or 2022.
In the meantime, alternative drug treatments are desperately needed as hospitals are once again reaching maximum capacity all over the world. Many countries such as the United Kingdom, Germany, and Italy are going through a second, strict lockdown due to rising cases. In the United States, they've recently recorded nearly 100,000 cases in a single day.
Other countries such as Israel and Singapore have been going through circuit breaker lockdowns as well, or a mini-lockdown that only lasts a few short weeks, whenever cases rise again. Despite other countries going back to pre-pandemic normal such as China, millions are still suffering from coronavirus.
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