BCG vaccination in children with T1D — Yazd study
What this study tests
A small Iranian study reported two BCG doses versus saline in children with established T1D. Its 18-month HbA1c finding is a within-BCG-group comparison, with no corresponding control value in the table and conflicting figure text. The publication-reported trial registration and current status remain unconfirmed.
Editorial review: . 16 September review-note archive (earlier notes may not cover later changes).
Most recent recorded citation date: 2026-03-10. Only explicit date metadata is included; an undated citation may be newer. This does not mean every claim was reviewed on that date.
Trial status, labels and access can change between reviews. Review coverage and open work · How to read the evidence
Evidence at a glance
- Who can enter the study?
- The publication describes children aged 6–14 with T1D for at least one year, HbA1c above 7% and insulin treatment. It excluded several diabetes complications, chronic infection, immune deficiency, immunosuppressive treatment and other conditions. These are historical study criteria, not a current recruitment offer.Enrollment criteria describe who may enter. They do not establish who was analyzed or the denominator for a reported result.
- Reported benefit and results
- Results and Figure 1 report 33 randomized: 17 to BCG and 16 to control, with one BCG withdrawal and 16 analyzed per group. Table 3 reports BCG HbA1c of 9.49% at baseline and 8.87% at 18 months; the control's 18-month value is missing and Figure 2 instead prints 8.78%. This does not establish a between-group benefit. C-peptide did not change significantly. The authors reported no local or systemic adverse effects, with limited safety detail in a small selected sample.Read the result sources and their limitations →
- Important harms
- Read the reported results, safety discussion and original sources. A separate harms summary is not available; this does not establish safety.
- Research access and approval
- Study regions: Other regions. A trial listing does not establish product approval or current recruitment at a particular site. Check the study’s current entry requirements.
- What remains uncertain?
- Read the 16 September review-note archive and current review coverage. Later changes and new records may not appear in the earlier notes. Planned endpoints and completion dates are not results.
Research status alone does not establish approval, clinical benefit or local availability.
Primary endpoints
- HbA1c, described as the primary outcome in the publication; reported follow-up extends to 18 months, but the control table has no 18-month value
The full picture
Study design and participants
The paper describes a single-center study at the Yazd Diabetes Research and Treatment Center in Iran. Its title calls the design quasi-experimental, while Methods describes computer-generated random allocation, concealed assignment and double blinding. Children received two BCG injections or saline four weeks apart alongside insulin therapy. These are the authors' reported methods; the trial registration was not independently retrieved.1
Methods describes a sample-size plan of 16 per group. Results and Figure 1 report 33 randomized: 17 assigned BCG and 16 assigned control. One BCG participant withdrew after the first dose, leaving 16 analyzed per group. The 32-person analysis is therefore not the same as the randomized population.1
What the outcome report supports
HbA1c was the stated primary outcome. Table 3 and Results give BCG-group HbA1c of 9.49% at baseline and 8.87% at 18 months, with a reported p value of 0.01. The control row ends at 12 months and has a dash at 18 months. Figure 2 instead prints 8.78% at 18 months. These unresolved reporting differences prevent treating the result as a demonstrated 18-month advantage over placebo.1
C-peptide, anti-GAD and anti-ICA testing was confined to the BCG group. The paper reports no significant C-peptide or anti-GAD change and a reduction in anti-ICA; these within-group findings do not establish beta-cell restoration. The report provides no evidence of insulin independence.1
Harms and reporting limits
The authors report no local or systemic adverse effects. The report provides no detailed adverse-event table or clear safety-analysis denominator, so this should not be restated as a proven 0/32 risk. A small selected study cannot establish the absence of uncommon harms.1
The timeline also needs clarification. Methods describes patients referred from October 2021 to May 2023; Results says enrollment ran from October 2021 to May 2022. Figure 1 labels follow-up as 32 weeks, whereas the text and HbA1c table extend to 18 months. No single reconciled follow-up schedule is established by this report.1
Registration and access
The publication gives IRCT20201012049003N1 and a registration date of 15 October 2020. An official registry record could not be retrieved during this review, so registry details, formal trial phase and current recruitment status remain unconfirmed. This is a historical outcome report, not an invitation to obtain BCG for T1D or a result from the separate US BCG trials.1
References
Sources
- [1]Bacillus Calmette-Guerin in controlling type 1 diabetes: A quasi-experimental randomized clinical trial · Peer-reviewed study · 2026-03-10 — Full original text, tables and PDF figures reviewed. Results and flow diagram distinguish 33 randomized from 32 analyzed. Conflicting follow-up labels and HbA1c figure/table values remain unresolved. IRCT registration is reported by the publication; no official registry record was retrieved.