When to boost? new trial seeks best COVID-19 shot timing for vulnerable patients
NCT ID NCT05415267
First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time
Summary
This study looks at 320 adults who are about to start strong immune-suppressing therapy and have already had at least two COVID-19 shots. Researchers want to find out if giving a COVID-19 booster right before starting therapy or waiting six months provides better protection. Participants will also receive a diphtheria/tetanus booster to compare how the immune system responds to different vaccines.
What this could mean
Our plain-language read of the trial. This is informational only — not medical advice or a prediction.
Active substance
COVID-19 booster vaccine and diphtheria/tetanus toxoids vaccine
What this could lead to
If successful, this could help doctors choose the best time to give COVID-19 boosters to people starting immunosuppressive therapy, improving their protection against severe illness.
What could go wrong
This is a Phase 3 trial, but it focuses on timing rather than a new treatment. Results may not apply to all types of immunosuppression or vaccines, and individual responses may vary.
Disclaimer
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This is a summary of
the original study
.
Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
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Study contacts
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Contact
Phone: •••-•••-•••• Email: •••••@•••••
Locations
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Blacktown Hospital
RECRUITINGBlacktown, New South Wales, 2148, Australia
Contact Email: •••••@•••••
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Concord General Repatriation Hospital
RECRUITINGConcord, New South Wales, 2137, Australia
Contact Email: •••••@•••••
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Royal Prince Alfred Hospital
RECRUITINGCamperdown, New South Wales, 2050, Australia
Contact Email: •••••@•••••
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St Vincent's Hospital, Sydney
RECRUITINGDarlinghurst, New South Wales, 2010, Australia
Contact Email: •••••@•••••
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Westmead Hospital
RECRUITINGWestmead, New South Wales, 2145, Australia
Contact Email: •••••@•••••