Differential Activity of Repurposed Drugs as Receptor Binding Domain Antagonists for Omicron and Native Strains of SarsCov2

Omicron strain is the latest variant of concern of SarsCov2 virus. The mutations in this strain in the S protein Receptor Binding domain (RBD) enable it to be more transmissible as well as escape neutralizing activity by antibodies in response to vaccine. Thus, Omicron specific strategies are need to counter infection by this strain. We investigated a collection of approved drugs shown to antagonize the binding of native strain RBD to human ACE2, for their ability to antagonize binding to Omicron strain RBD. While most of the drugs the drugs that antagonize binding to native RBD are also active for Omicron RBD but some were inactive, namely drugs that contain iodine are completely inactive against Omicron RBD. Our data strongly indicate that presence of a single iodine molecule in the drug renders it inactive against Omicron strain. Thus, there is molecular specificity of drugs for antagonizing Omicron strain RBD versus native strain RBD of this virus. Such information will pave way for specific drugs for Omicron. A pragmatic message from our data is that the often-used iodine containing mouth wash and rises may be ineffective in antagonizing receptor binding of Omicron strain.

Edible formulations of chicken egg derived IgY antibodies neutralize SarsCoV2 Omicron RBD binding to human ACE2

SarsCoV2 virus driven pandemic continues to surge propelled by new mutations such as seen in Omicron strain. Omicron is now rapidly becoming the dominant strain globally with more than 30 mutations in the spike protein. The mutations have resulted in Omicron strain escaping most of the neutralizing antibodies generated by the current set of approved vaccines and diluting the protection offered by the vaccines and therapeutic monoclonal antibodies. This has necessitated the need for newer strategies to prevent this strain from spreading. Towards this unmet need we have developed chicken egg derived anti-RBD IgY antibodies that neutralize the binding of Omicron RBD to human ACE2. Furthermore, we have formulated the edible IgY as flavored beverages to allow for use as oral rinse and prevent the entry of Omicron in the oropharyngeal passage, a major access and accumulation point for this strain in humans.

Preparation of ingestible antibodies to neutralize the binding of SarsCoV2 RBD (receptor binding domain) to human ACE2 Receptor

COVID19 continues to be a serious threat to human health and mortality. There is dire need for new solutions to combat this pandemic especially for those individuals who are not vaccinated or unable to be vaccinated and continue to be exposed to the SARSCoV2. In addition, the emergence of new more transmissible variants such as delta pose additional threat from this virus. To explore another solution for prevention and treatment of COVID 19, we have produced chicken egg derived IgY antibodies against the Receptor binding domain (RBD) of SARSCoV2 spike protein which is involved in binding to human cell ACE2 receptors. The - RBD IgY effectively neutralize the binding of RBD to ACE2 and prevent pseudovirus entry in a PRNT assay. Importantly our anti-RBD IgY also neutralize the binding of Sars CoV2 delta variant RBD to ACE2. Given that chicken egg derived IgY are safe and permissible for human consumption, we plan to develop these ingestible antibodies for prevention of viral entry in the oropharyngeal and digestive tract in humans as passive immunotherapy.