Director, Michael G. DeGroote Institute for Infectious Disease Research (IIDR), McMaster University
McMaster University’s next-generation COVID-19 vaccines will be delivered by aerosol, directly targeting the respiratory tract, where infections take hold.
The SARS-CoV-2 virus that causes COVID-19 is a coronavirus, as are many viruses responsible for ongoing, seasonal common cold-like infections. Like influenza virus, coronaviruses are notable for their capacity to mutate, which has resulted in the emergence of SARS-CoV-2 variants. The first-generation COVID-19 vaccines are a poor match for the variants that are causing infections now, which has necessitated regular boosting and attempts to update the vaccines.
“This leaves scientists in a situation where we’re always one step behind the virus, and that’s not an enviable position to be in,” says Matthew Miller, Director of the Michael G. DeGroote Institute for Infectious Disease Research (IIDR) at McMaster University, a world-leading centre of transdisciplinary infectious disease research. Miller and his team at the IIDR are taking a fresh approach to virology and vaccinology, building off decades of research at McMaster to get ahead of the virus and protect people better.
An innovative new approach
“The limitation of the current COVID vaccines authorized in North America is that they only target the spike protein, which is just one of many components of the virus,” says Miller, who is also an investigator with Canada’s Global Nexus for Pandemics and Biological Threats, which is based at McMaster. “And it’s the spike protein that the virus changes most quickly as it’s evolving to escape the immune response.”
So while COVID vaccines are now being updated with Omicron-specific spikes to better match the currently-circulating virus, Miller and his team saw a better way. “Our new approach was to develop a vaccine that not only targets the spike but also other components of the virus that don’t change very much as the virus evolves and new variants emerge,” he explains.
Miller and his team applied the field’s recent understanding of immune responses capable of recognizing a broader and more diverse set of viruses to the SARS-CoV-2 virus.
Transforming vaccine delivery
Not only do the McMaster vaccines act more broadly against virus variants, but they’re delivered in a new, more targeted format: inhaled directly through the mouth and into the lungs via an aerosolized mist.
“All currently-approved COVID vaccines are injected,” says Miller. “When we inject them, we tend to stimulate strong antibodies and T cells that circulate in the blood and are distributed throughout the body. That’s great if you’re trying to protect someone from infections that are spread throughout the body, but it’s not as ideal if you’re trying to protect someone from respiratory infections.”
Building on over a decade of pioneering work on inhalable vaccines for tuberculosis, the McMaster team applied its learnings to the new COVID vaccines. “This elegant system we’ve developed to deliver the vaccine into the lungs is very unique and has really placed McMaster at the forefront of what is now being referred to as mucosal vaccines,” says Miller. “Most other groups who study these types of vaccines are focusing on nasal sprays, which do not deliver the vaccine deep into the lungs where severe infections occur.”