Phase 2 Clinical Trial Evaluating an Inhaled Aerosol COVID-19 Vaccine

Because COVID-19 is an infection which mainly infects the lung, we want to study whether giving the vaccine by inhalation into the lungs is safe in humans who have already had at least three doses of an mRNA COVID vaccine. We also want to study what sort of immune response (protection level) develops in the blood after receiving the study vaccine.

Public health measures such as testing, isolation and quarantine, masks, and physical distancing have helped to control COVID-19, however vaccination is the best way to control the virus. The widespread administration of COVID vaccines has led to fewer infections, less severe disease, and fewer deaths. However, new strains of COVID (called variants-of-concern) have been spreading that are not as well controlled by the current vaccines. It is important that we keep doing research to develop new kinds of COVID-19 vaccines that work differently and could be used to boost immunity to provide extra protection against the virus.

The study vaccine, called ChAd-triCoV/Mac, is a new type of COVID-19 vaccine. It has been studied previously in over 20 healthy people in a Phase 1 study. The study vaccine was developed by researchers at McMaster University and is manufactured in compliance with GMP (Good Manufacturing Practice) at the Robert E. Fitzhenry Vector Laboratory at McMaster University.

In the dose being used in this study, the study vaccine has been safe and has shown promising immune responses in the lung.

You may be eligible if:

• You are generally healthy;
• You are 18-65 years old;
• You have received at least 3 doses of an mRNA COVID-19 vaccine;
• You agree to practice adequate birth control for 8 weeks post vaccination if you are able to get pregnant.

Study staff will discuss any additional requirements with you before agreeing to take part.

• Breathing in a mist-like study vaccine or a saline mist placebo (this will be given through a nebulizer, which is a machine that turns liquid medicine into a fine mist that can be inhaled directly into the lungs);
• Recording your temperature and any symptoms at home;
• Four (4) clinic visits;
• Three (3) follow-up phone calls.

Participation in the study will last about 6 months.

This is a double-blind study, which means that neither you, the study doctors, the study staff, nor your usual health care providers will know whether you received the study vaccine or placebo. If medically necessary, this information can be obtained. Information about which vaccine you received will be available after the study has been completed and the results have been analyzed (in about 2 years).

Study staff will discuss all requirements with you in detail before agreeing to take part.