A Trial of a Next Generation COVID-19 Vaccine Delivered by Inhaled Aerosol

A Phase 2 Trial to Evaluate Safety and Immunogenicity of a Next-generation COVID-19 Vaccine Delivered by Inhaled Aerosol to Humans

A Trial of a Next Generation COVID-19 Vaccine Delivered by Inhaled Aerosol (NCT06381739) is a Phase 2 interventional studying COVID-19 Infection, sponsored by McMaster University. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

The goal of this clinical trial is to study the safety of a new inhaled vaccine to prevent COVID infection and learn about the immune responses that are made in the lungs and the blood after vaccination. Participants will be randomized (like the toss of a coin) to receive the experimental vaccine or a placebo (a look-alike solution that contains no vaccine). To be in the study participants will have to have already had three doses of a messenger ribonucleic acid (mRNA) COVID vaccine and be generally healthy. Participants are given a single dose of the vaccine by breathing in a fine mist that goes directly into the lungs. During follow-up participants will: * visit the clinic for checkups and blood tests at 2, 4 and 8 weeks after vaccination * report their symptoms for 24 weeks after getting the vaccine. In some participants, the researchers will collect cells from the lung 4 weeks after vaccination (a test known as a bronchoscopy).

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against COVID-19 Infection and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

A target enrollment of 350 participants makes this a sizable late-stage trial. Studies in this range typically have enough power to detect clinically meaningful differences from a comparator and to characterize less-common side effects.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Adults who are 18-65 years old on the day of randomization (day 1) 2. Able to read, write and communicate using the English or French language. 3. Received at least 3 doses of an mRNA COVID vaccine. 4. Individuals of childbearing potential must have a negative pregnancy test prior to vaccination and be willing to practice effective contraception for 8 weeks post-vaccination. 5. Able to understand and comply with protocol requirements and instructions; able to report adverse events; able to attend scheduled study visits and complete required investigations. 6. For participants in the BAL sub-study, Complete Blood Count (CBC) and chemistry (creatinine) within normal limits. 7. For participants in the BAL sub-study, forced expiratory volume in 1 second (FEV1) \> the lower limit of normal (LLN), and FEV1/FVC (forced expiratory volume in 1 second/forced vital capacity) ratio above the LLN. 8. Agree not to enroll in any other intervention studies for the duration of the study where the intervention could be reasonably expected to be associated with adverse events overlapping with the inhaled vaccine or the immune responses being measured. Who Should NOT Join This Trial: 1. Failure to provide willing to sign a consent form. 2. Women who are pregnant or breastfeeding. 3. Have received any recombinant adenoviral-vectored COVID-19 vaccine (AstraZeneca \[Vaxzeria\] or Johnson \& Johnson (Janssen Jcovden). 4. COVID infection (positive PCR or antigen (Ag) test, self-reported or lab documented) within the last 90 days. 5. Last dose of a COVID vaccine administered less than 90 days prior to study entry. 6. Administration of any vaccine within 2 weeks of study entry. 7. Active pulmonary disease diagnosed by a physician including asthma, chronic bronchitis, interstitial lung disease, pulmonary hypertension, lung cancer, cystic fibrosis, or bronchiectasis. Current use of daily inhaled steroids for any condition. ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion criteria: 1. Adults who are 18-65 years old on the day of randomization (day 1) 2. Able to read, write and communicate using the English or French language. 3. Received at least 3 doses of an mRNA COVID vaccine. 4. Individuals of childbearing potential must have a negative pregnancy test prior to vaccination and be willing to practice effective contraception for 8 weeks post-vaccination. 5. Able to understand and comply with protocol requirements and instructions; able to report adverse events; able to attend scheduled study visits and complete required investigations. 6. For participants in the BAL sub-study, Complete Blood Count (CBC) and chemistry (creatinine) within normal limits. 7. For participants in the BAL sub-study, forced expiratory volume in 1 second (FEV1) \> the lower limit of normal (LLN), and FEV1/FVC (forced expiratory volume in 1 second/forced vital capacity) ratio above the LLN. 8. Agree not to enroll in any other intervention studies for the duration of the study where the intervention could be reasonably expected to be associated with adverse events overlapping with the inhaled vaccine or the immune responses being measured. Exclusion criteria: 1. Failure to provide informed consent. 2. Women who are pregnant or breastfeeding. 3. Have received any recombinant adenoviral-vectored COVID-19 vaccine (AstraZeneca \[Vaxzeria\] or Johnson \& Johnson (Janssen Jcovden). 4. COVID infection (positive PCR or antigen (Ag) test, self-reported or lab documented) within the last 90 days. 5. Last dose of a COVID vaccine administered less than 90 days prior to study entry. 6. Administration of any vaccine within 2 weeks of study entry. 7. Active pulmonary disease diagnosed by a physician including asthma, chronic bronchitis, interstitial lung disease, pulmonary hypertension, lung cancer, cystic fibrosis, or bronchiectasis. Current use of daily inhaled steroids for any condition. 8. Persons with HIV and a detectable HIV viral load (\>20 copies/mL), self-reported or confirmed. 9. Administration of monoclonal antibodies for treatment of COVID-19 infection within 3 months. 10. Moderately or severely immunocompromised (e.g. transplant recipients/CAR-T cell therapy, currently on chemotherapy for cancer or on potent immunosuppressant therapies e.g. rituximab or high dose steroids \[\>30 mg of prednisone equivalent daily\], or moderate or severe primary immunodeficiency syndrome). 11. History of severe reaction to previous COVID vaccination (e.g. hives, difficulty breathing, high fever, seizures, myocarditis, pericarditis)). 12. Potential contraindication to COVID vaccination (e.g. venous or arterial thrombosis with thrombocytopenia after vaccination, history of cerebral venous thrombosis with thrombocytopenia, history of heparin induced thrombocytopenia, history of myocarditis or pericarditis). 13. Known allergy to vaccine components or previous receipt of any experimental adenovirus-vector vaccine by the aerosol route. 14. Enrolment in any clinical trial of experimental treatment for COVID infection within 90 days. 15. For participants in the BAL sub-study, any health-related condition for which study bronchoscopy is contraindicated. 16. For participants in the BAL sub-study, current use of anticoagulants.

Treatments Being Tested

BIOLOGICAL

ChAd-triCoV/Mac

Clinical-grade, fully certified ChAd-triCoV/Mac produced according to current Good Manufacturing Principles (cGMP) will be provided. A single dose of ChAd-triCoV/Mac diluted in 0.5mL formulated buffer will be aerosolized and inhaled via a mouthpiece and tidal breathing over approximately 2 minutes using the AeroNeb Solo Mesh Nebulizer.

OTHER

Control

A single dose of placebo (0.5mL formulated buffer) will be aerosolized and inhaled as the intervention vaccine.

Locations (2)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Canadian Center for Vaccinology, Dalhousie University

Halifax, Nova Scotia, Canada

Health Sciences Centre

Hamilton, Ontario, Canada

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06381739), the sponsor (McMaster University), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06381739 clinical trial studying?

The goal of this clinical trial is to study the safety of a new inhaled vaccine to prevent COVID infection and learn about the immune responses that are made in the lungs and the blood after vaccination. Participants will be randomized (like the toss of a coin) to receive the experimental vaccine or a placebo (a look-alike solution that contains no vaccine). To be in the study participants will have to have already had three doses of a messenger ribonucleic acid (mRNA) COVID vaccine and be generally healthy. Participants are given a single dose of the vaccine by breathing in a fine mist that … The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT06381739?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06381739?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06381739. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06381739. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.