A neutralizing VHH-based antibody
Since the start of the COVID-19 outbreak, the team of professor Xavier Saelens has been working relentlessly on a potential treatment for the viral infection. Earlier work of the scientists identified a single-domain antibody (VHH) that can prevent the binding of the SARS-CoV-2 Spike protein to human ACE2, the receptor of this virus that is present on the cell surface. The Spike protein mediates the initial stage of infection: the viral entry into human cells.
Today, the lab announces new findings, in cooperation with the labs of Jason McLellan (University of Texas at Austin, US) and Markus Hoffmann and Stefan Pöhlmann (German Primate Center – Leibniz Institute for Primate Research, Göttingen, Germany), showing that Fc fusions of the VHH can neutralize pseudotyped SARS-CoV-2 (a recombinant reporter version of the virus).
En route to protection
These lab tests provide the first evidence that the VHHs can neutralize the new coronavirus. Importantly, the neutralizing VHH can be produced in large-scale production processes that are common in the biopharmaceutical industry.
Prof. Saelens emphasizes: “This important step forward in the fight against COVID-19 is the result of great teamwork by members of my lab and professor Nico Callewaert’s research group (VIB-UGent Center for Medical Biotechnology).”
Dr. Bert Schepens, staff scientist in the team of Prof. Saelens: “Good teamwork is crucial. We can count on the expertise in the research center, colleagues from VIB Discovery Sciences and the VIB Innovation & Business team. We will continue these collaborations, also with academic experts outside VIB. The moment we observed virus neutralization in these experiments really felt like a collective victory.”
In contrast to vaccines, an antibody offers immediate protection – though of shorter duration. The advantage of this approach over vaccines is that patients don’t need to produce their own antibodies. The most vulnerable groups, such as the elderly, often mount a modest response to vaccines, which means that their protection may be incomplete. Healthcare workers or people at increased risk of exposure to the virus can also benefit from an immediate protection. This type of medicine can therefore be an important tool in fighting the current pandemic.
The next steps
It remains important to note that confirmation of these results using the pathogenic coronavirus strain is needed – experiments which are currently ongoing. The VIB researchers are also preparing the preclinical test phase for a coronavirus treatment. Although these first results are highly promising, further research is necessary to confirm the full potential of this antibody-based drug directed against COVID-19.