MVA-vectored universal beta-coronavirus vaccine design & development
Vaccine Insights 2023; 2(5), 201–211
DOI: 10.18609/vac.2023.032
Coronaviruses capable of infecting humans have circulated within the population and are well known to the scientific community. These viruses generally cause mild-moderate and recurring respiratory infections but pose minimal serious health risks. However, the more recent emergence of SARS-CoV-1, CoV-2, and MERS clearly demonstrate the risk of new coronavirus ‘spillover events’ from animal hosts, and this risk can be addressed proactively. A significant level of antigenic variation exists for the Spike protein amongst the coronaviruses that can infect humans and include the evolving variants of SARS-CoV-2. This is a well-recognized hurdle for vaccine development where the focus is on the induction of neutralizing antibody responses. However, a significant level of sequence and antigenic similarity is also known to exist, especially for the nucleocapsid, membrane proteins, and most of the non-structural proteins, and these conserved proteins are targets of the T cell arm of the immune system. Using modern viral vector-based vaccine technologies, it is feasible to design and develop vaccines capable of inducing T cell responses specific to multiple conserved viral proteins, providing a breadth of antiviral function and specificity. Vaccines of this type could serve as the basis for better targeting both SARS-CoV-2 as well as other beta-coronaviruses in a controlled prevention manner. This type of vaccine could be used as a booster to standard-of-care products or specifically for the benefit of unique patient populations where vaccine failure is common. Critically, we could return to a focus on prophylaxis, the prevention of disease through controlled vaccine campaign strategies using products that induce durable immune responses, including immunological memory.