Inhaled Canadian COVID-19 vaccine to enter Phase 2 human trials

A new made-in-Canada COVID-19 vaccine that can be inhaled is set to enter Phase 2 human trials.

The vaccine is being developed at McMaster University in Hamilton, Ont.

"There is a pressing need to develop new, more effective next-generation vaccine strategies," McMaster's vice-president of research, Dr. Karen Mossman, said in a news release. "As international leaders in respiratory mucosal immunity and vaccines, our researchers pivoted quickly with the arrival of the COVID-19 pandemic, drawing on an already strong inhaled vaccine research program focused on tuberculosis."

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Pre-clinical trials have already shown that the inhaled aerosol vaccine can be more effective at creating immune responses than injected vaccines, partly because it targets the upper airways and lungs where respiratory viruses like COVID-19 enter the body, according to the release.

During Phase 1 of the human trials, researchers have been evaluating dosage and safety in 30 healthy volunteers who have already received at least two shots of an mRNA vaccine, like those made by Pfizer and Moderna.

In Phase 2, set to begin in the coming months, researchers will monitor safety and immune responses in up to 500 participants, including those with other health conditions, who have received at least three mRNA vaccine doses. Phase 2 will be conducted with the help of $8.2 million in new federal funding from the Canadian Institutes for Health Research.

Dr. Fiona Smaill is a professor in McMaster's pathology and molecular medicine department, and one of the leaders of the clinical trials, which also includes collaborators from Dalhousie University in Nova Scotia and the University of Ottawa.

"If we can show the new inhaled vaccine is safe and effective, as we anticipate, the impact will be significant for human health, medical costs and better quality of life," Smaill said.

The vaccine is meant to target parts of the coronavirus that do not change or mutate, potentially making it more effective against new variants.

"The current vaccination strategy for COVID-19 has us constantly chasing the virus, and it’s clear that we simply can’t keep up," explained Matthew Miller, scientific director of McMaster's infectious disease research institute, and one of the trial's leaders. "Our team has developed a vaccine strategy aimed at circumventing this cycle and the need to constantly update these vaccines by targeting parts of the virus that are resistant to mutation, and inducing strong immunity at the site where infection actually occurs."

Amid pandemic fatigue and declining booster numbers, the researchers hope an inhaled vaccine will be more convenient and appealing than needles, and they anticipate their work will help advance inhaled vaccines for other respiratory infections like tuberculosis and influenza.