Toward a protective Covid-19 vaccine utilizing an established vector platform

Abstract The recently emerged coronavirus SARS-CoV-2, the causative agent of COVID-19, is rapidly spreading in the world with over 4,8 million cases, and 320,000 deaths as of May 16, 2020. This novel coronavirus is thought to have emerged from a live animal market in Wuhan, China. It has quickly spread in the community with large clusters of human-to-human transmission. Sequencing of several isolates has determined that the most closely related strains are SARS-like bat coronavirus lineages. The susceptibility of SARS-CoV-2 to anti-viral compounds, its ability to replicate in cell lines or host factors regulating its replication are all currently unknown. Importantly, there are no therapeutics available to treat the virus, although investigational studies are underway. Modelling of the current outbreak suggests that the virus could infect >1 billion people and become a yearly epidemic. Identifying people who have developed antibodies is important for the epidemiology as well as patient care. With the exponentially expounding threat of SARS-CoV-2 to global health, a vaccine is desperately needed. Herein we propose the development of a novel, highly efficacious and safe COVID-19 vaccine with facile scale up potential. Our proposal uses a rabies virus-based vector that has proven to be an efficient vaccine against emerging and re-emerging infectious diseases. We have demonstrated that inactivated rabies virus particles containing the coronavirus (CoV) spike S1 protein induce potent immune responses and provide protection in animal systems against Middle Eastern Respiratory Syndrome coronavirus (MERS) and Severe Acute Respiratory Syndrome (SARS) coronavirus, both of which are highly related to SARS-CoV-2. A similar vaccine entitled CoraVax™ is available and herein we propose to analyze CoraVax™ immunogenicity in mice as well as its abilty to protect in a hamster model.