The compressed air passes through a narrow orifice, sucking drug solution from a reservoir and into a feed tube, before making its way as a fine mist to the lungs and upper airways.
It’s called a jet nebulizer — a medical tool similar to an asthma puffer that takes just minutes to send medicine to the heart of respiratory pathogens.
It’s also what local researchers believe could be the most effective route of delivery for COVID-19 vaccines.
Beginning this month, a team of McMaster University scientists will use the machine to administer two new, oral coronavirus vaccines just approved for human trials by Health Canada.
The promising Hamilton-made vaccines, delivered by inhaled aerosols, go straight through the breathing passage to provoke an immune response in the lungs — right where the virus attacks.
They’re designed to combat variants of concerns and provide
broader protection from COVID-19, said Dr. Fiona Smaill, the McMaster professor of pathology and molecular medicine who is leading the clinical trial.
“It’s administered into the lungs so the immune response is generated in the lungs,” Smaill said in an interview Monday. “And it’s really in the lungs where you need the immune response because it’s the first line of defence against a respiratory pathogen like COVID.”
With the vaccines currently in use, injected into the muscle, Smaill said “you’re hoping that some of the cells” generated by them make their way into the lungs.
But that’s not a guarantee — unlike with these new vaccines, which are delivered straight to the upper airways.
“That’s much more effective than giving an injection into the muscle, where the immune response is typically generated within the blood,” she added.
What’s different about the McMaster vaccines, besides how they’re delivered, is in the proteins they target.
First-generation COVID vaccines, such as Pfizer-BioNTech or Moderna, target the large spike protein that protrudes from the surface of the SARSCoV-2 virus that causes COVID. Mac’s vaccines, meanwhile, will target three different parts of the coronavirus: the spike protein plus two other areas on the virus that aren’t as suspectible to mutations.
“Some of these proteins pretty well stay the same from variant to variant, unlike the spike protein, which is very, very (likely) to mutate,” Smaill explained. “And that’s what the concern is about the existing vaccines — that they target only the original spike and may be waning in effect.”
Of the 21 vaccines approved for clinical trials in Canada, the McMaster vaccines are the only ones delivered orally.
At least 30 healthy volunteers who have received two doses of a COVID mRNA vaccine will take part in the study, which is expected to run for three to six months.
Researchers will examine how the immune response develops in the lungs and blood after vaccination and monitor for possible side effects.
Smaill said the “first class” team of Mac scientists has manufactured enough doses to move forward with a larger trial should the first phase prove successful, potentially leading to broader use.