Pancoronavirus Vaccine Study in Healthy Adults

Coronaviruses (CoVs) have caused the severe acute respiratory syndrome (SARS) outbreak, the Middle East Respiratory Syndrome (MERS) outbreak, and now the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Although there are several approved or authorized vaccines for SARS-CoV-2, there are currently no vaccines approved to prevent diseases caused by multiple different coronaviruses. Two countermeasures with promise for controlling coronavirus outbreaks are recombinant neutralizing antibodies and vaccines directed against the virus. Between these two countermeasures, the ultimate solution to control the current COVID-19 pandemic and future CoV outbreaks is a pancoronavirus vaccine. In particular, a vaccine that can induce broader protection and can prevent severe disease caused by current SARS-CoV-2 variants of concern would help mitigate significant morbidity and mortality following SARS-CoV-2 infection. Additionally, an optimal pancoronavirus vaccine would prevent severe disease from other SARS-related viruses in the genus of coronaviruses-betacoronavirus-that are responsible for past outbreaks or could cause the next major outbreak in humans. Such a broadly active coronavirus vaccine would be an impactful first step towards preventing all life-threatening coronavirus human disease. The proposed vaccine immunogen (Cov-RBD-scNP-001) is composed of an engineered receptor binding domain (RBD) of SARS-CoV-2 WA-1 covalently linked in vitro to the surface of a Helicobacter pylori ferritin protein nanoparticle (RBD-scNP). The RBD has been engineered at two sites to improve its expression. The protein nanoparticle is composed of 24 individual ferritin subunits each of which can have a SARS-CoV-2 WA-1 RBD attached to it via a nine amino acid linker. The protein nanoparticle will be delivered with 3M-052-AF adjuvant - a TLR 7/8 agonist.