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Phase 2Active, not recruitingNCT05180591

Repeat BCG vaccination in pediatric T1D

Pediatric phase 2 trial testing repeat BCG vaccination in children and adolescents with established T1D. Enrolment has closed at 150 participants and the trial is now in long follow-up — primary completion is not estimated until March 2031, so no near-term readout should be expected.

Primary endpoints

  • Change in HbA1c values

Results so far

No results posted. Enrolment is closed at 150 participants and the trial is in the follow-up phase; primary completion is estimated for March 2031, so results are years away.

The full picture

What is being tested, and why

Bacillus Calmette-Guérin (BCG) is a century-old tuberculosis vaccine that also nudges the immune system in ways researchers hope might calm the autoimmune attack behind type 1 diabetes. This trial, run by Massachusetts General Hospital, gives children and adolescents aged 8–17 who already live with established T1D repeat BCG shots or saline placebo injections, and follows what happens to their HbA1c.1

Where it stands today (July 2026)

Enrolment has closed. The registry now lists the trial as active, not recruiting, with 150 participants signed up — so it is no longer open to new volunteers.1

The more important thing for anyone tracking BCG is the timeline: primary completion is estimated for March 2031. This is a long follow-up study, not a near-term readout. No efficacy results have been posted, and on the current plan none should be expected for several more years.1

How to read this

BCG in T1D remains an unproven, open question. Earlier BCG work in this field has been contested, and this trial exists precisely because the question has not been settled. A parallel Massachusetts General trial tests the same repeat-BCG idea in adults with established T1D, and it too is closed to enrolment and still in follow-up.2 Until these trials report, there is no good evidence that BCG improves glucose control in T1D — the honest status is "being tested", not "works".

References

  1. Massachusetts General Hospital. Repeat BCG Vaccinations For The Treatment Of Pediatric Type 1 Diabetes, NCT05180591. ClinicalTrials.gov (last update 2026-06-23). https://clinicaltrials.gov/study/NCT05180591 ↩ ↩2 ↩3

  2. Massachusetts General Hospital. Repeat BCG Vaccinations for the Treatment of Established Type 1 Diabetes, NCT02081326. ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT02081326 ↩