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Recruiting Phase 3 NCT05415267

NCT05415267 Immunosuppression and COVID-19 Boosters

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Clinical Trial Summary
NCT ID NCT05415267
Status Recruiting
Phase Phase 3
Sponsor Kirby Institute
Condition COVID-19
Study Type INTERVENTIONAL
Enrollment 320 participants
Start Date 2023-07-21
Primary Completion 2026-12-31

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
diphtheria and tetanus toxoids (adsorbed) vaccineCOVID-19 vaccine

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

Phase 3 trials are large pivotal studies comparing the treatment to current standard of care or placebo. Your participation directly contributes to the evidence needed for regulatory approval.

This trial targets 320 participants in total. It began in 2023-07-21 with a primary completion date of 2026-12-31.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

It is important people receiving immunosuppressive therapy are provided with the best protection against COVID-19 because they are at greater risk of severe illness should they become infected. As severe immunosuppression can reduce the efficacy of COVID-19 vaccination, doctors agree that COVID-19 boosters is are important to maximise the vaccine response in these people. However, we don't currently know the best time to give booster vaccines to people about to start immunosuppressive therapy. This research aims to address this knowledge gap by examining whether the greatest protection is provided by giving the COVID-19 booster just before the immunosuppressive therapy starts or by waiting and giving the booster 6 months after treatment start. At the 6-month timepoint, in many cases the more intensive immunosuppression is often weaning and the immune system is starting to rebuild.

Eligibility Criteria

Inclusion Criteria: * Adult aged at least 18 years * Previously vaccinated with 2 (or more) doses of any licensed COVID-19 vaccine who requires initiation of moderate-to-severe immunosuppression; most recent COVID-19 vaccine dose must have been given \> 3 months prior * Planned significant immunosuppressive therapy for at least 1 year * No cyclophosphamide, alemtuzumab or rituximab treatment in the past 5 years. Note: patient may have concurrent steroids with any treatments listed in protocol * Voluntarily given written informed consent Exclusion Criteria: * Pregnant or breastfeeding * Has underlying primary immunodeficiency * Has received or likely to receive intravenous/subcutaneous immunoglobulin (IVIg/ScIg). * Projected treatment is likely to involve plasma exchange * Contraindication to receipt of SARS-CoV-2 vaccine * Intolerance of or previous allergic reaction to tetanus vaccination * Patients switching immunosuppressive therapies following enrolment with an absolute lymphocyte count \<0.5 x 109/L immediately prior to screening

Contact & Investigator

Central Contact

Dianne L Carey, PhD

✉ dcarey@kirby.unsw.edu.au

📞 +61 2 9385 0908

Principal Investigator

Sarah C Sasson, PhD

PRINCIPAL INVESTIGATOR

The Kirby Institute UNSW Sydney

Frequently Asked Questions

Who can join the NCT05415267 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, studying COVID-19. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT05415267 trial and what does that mean for participants?

Phase 3 trials are large-scale studies comparing the new treatment to existing standards of care or a placebo. They provide the evidence needed for regulatory approval. This trial targets 320 participants.

Is NCT05415267 currently recruiting?

Yes, NCT05415267 is actively recruiting participants. Contact the research team at dcarey@kirby.unsw.edu.au for enrollment information.

Where is the NCT05415267 trial being conducted?

This trial is being conducted at Blacktown, Australia, Camperdown, Australia, Concord, Australia, Darlinghurst, Australia and 1 additional location.

Who is sponsoring the NCT05415267 clinical trial?

NCT05415267 is sponsored by Kirby Institute. The principal investigator is Sarah C Sasson, PhD at The Kirby Institute UNSW Sydney. The trial plans to enroll 320 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: July 2026  ·  Data Methodology