Coronaviruses are a large family of evolving viruses, a large class of genetically diverse RNA viruses that exhibit a broad host range in mammals, and infection with coronaviruses causes a wide range of illnesses, from the common cold to severe disease and death.
Multiple zoonotic coronaviruses have evolved to infect humans and are highly contagious, pathogenic and even fatal, and have led to global pandemics. To date, seven known coronaviruses have evolved to infect humans, three of which are highly pathogenic human coronaviruses, namely Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2).
These three coronavirus outbreaks, which appeared in 2002, 2012, and 2019, respectively, can all lead to severe respiratory or multiorgan disease and possibly death. In particular, the new coronavirus pandemic caused by SARS-CoV-2 has had a huge impact on human health and the world economy. Therefore, it is important to develop effective vaccines against these three highly pathogenic coronaviruses.
Recently, researchers from Duke University School of Medicine, Yale University School of Medicine, and the University of North Carolina at Chapel Hill collaborated to publish a research paper in the journal Cell Reports entitled: Vaccine-mediated protection against Merbecovirus and Sarbecovirus challenge in mice.
The study developed a pan-coronavirus vaccine that achieved initial success in preventing infection with three different deadly coronaviruses (SARS-CoV, SARS-CoV-2 and MERS-CoV) in mice.
All three coronaviruses belong to the genus bata coronavirus, with SARS-CoV and SARS-CoV-2 belonging to the subgenus Sarbecvirus and MERS-CoV belonging to the subgenus Merbecovirus. Given the emergence of three human-lethal Sarbecvirus subgenus and Merbecovirus subgenus coronaviruses in just 20 years, the development of universal coronavirus vaccines against these important virus types has become a global public health priority.
An mRNA vaccine based on the SARS-CoV-2 spiny protein (S protein) did not protect mice against SARS-associated zoonotic viruses and SARS-CoV. This suggests that the new crown mRNA vaccine currently in use is unlikely to provide robust protection against SARS-associated related or SARS-CoV-2-related zoonotic viruses or highly evolved SARS-CoV-2 mutant strains that may emerge in the future.
In this study, the team constructed a trivalent sortase-coupled nanoparticle (scNP) vaccine using a receptor-binding domain (RBD) containing SARS-CoV-2, bat-associated coronavirus RsSHC014, and MERS-CoV. This trivalent vaccine, when administered to mice, induced serum-neutralizing antibodies against bat SARS-like coronaviruses, SARS-CoV, SARS-CoV-2 BA.1, SARS-CoV-2 XBB.1.5, and live viruses of MERS-CoV. More importantly, mice vaccinated with this vaccine did not become ill in the face of infection with either SARS-like virus (Sarbecovirus) or MERS-like virus (Merbecovirus).
This study demonstrated in animals that a vaccine against both Merbecovirus and Sarbecovirus infections is an achievable goal.
It is worth mentioning that on July 18, 2022, the team of Stacy Chen at Yale University School of Medicine published a research paper entitled: Multiplexed LNP-mRNA vaccination against pathogenic coronavirus species in the journal Cell Reports.
The study developed a lipid nanoparticle (LNP)-delivered mRNA vaccine (LNP-mRNA) against SARS-CoV-2 Delta, SARS-CoV, and MERS-CoV and tested how this multiplexed vaccine induced effective immune responses in animal models.
