Canadian Government Launches Trials for Groundbreaking Inhaled mRNA COVID Vaccine ‘AeroVax’

Hamilton, Canada — Canadian researchers have launched human trials for AeroVax, a groundbreaking inhaled mRNA-based COVID-19 vaccine aimed at boosting respiratory immunity and reducing the need for injection. The Phase 2 clinical study is led by McMaster University in partnership with the Canadian Institutes of Health Research (CIHR).

Early Phase 1 studies in Hamilton involving 36 adults showed that AeroVax is safe and effective at generating immune responses directly in the lungs, where COVID‑19 infection typically begins Western Standard. This Phase 2 trial will enroll approximately 350 participants aged 18 to 65, all of whom have previously received at least three doses of an mRNA COVID vaccine.

The randomized, double-blind trial is being conducted at multiple Canadian locations—including Hamilton, Ottawa, and Halifax. Roughly two-thirds of participants will receive the AeroVax inhaled dose, while the rest will receive a placebo. Researchers will closely monitor both safety and immune responses over a 24-week period.

AeroVax is delivered via a nebulizer device called AeroNeb Solo, generating a fine aerosol mist that targets the upper respiratory tract and lungs. The vaccine uses a chimpanzee adenovirus vector—ChAd‑triCoV/Mac—designed to express three different antigens from SARS‑CoV‑2: spike protein S1, nucleocapsid, and RNA polymerase. The aim is to trigger both mucosal and systemic immunity and potentially offer broader protection across variants.

Researchers say inhaled vaccines may offer advantages over traditional injections by stimulating immune defenses at the site of infection. The technology could also play a future role in defending against other respiratory illnesses, such as influenza, as well as in pandemic preparedness efforts.

Dr. Fiona Smaill, lead investigator at McMaster’s Michael G. DeGroote Institute for Infectious Disease Research, stressed the importance of exploring needle-free delivery systems to overcome vaccine hesitancy and enhance protection where it matters most.

The study builds upon existing research in Canada and abroad into mucosal immunization. Similar nasal and inhaled approaches are under development around the globe, with the goal of achieving so-called “sterilizing immunity”—blocking infection before it begins.

At press time, participant recruitment is ongoing. Eligible volunteers with residency in the trial regions are encouraged to learn more and enroll through the official AeroVax website.