Earlier this month a story announcing research about the
tuberculosis vaccine helping people living with type 1 diabetes was
widely covered in the international media - but the reporting of
the facts has been questioned.
The American Diabetes Association (ADA) and JDRF on Tuesday
issued a joint statement clarifying the findings and their
importance to diabetes research.
According to the research from Massachusetts General Hospital,
which was originally published in the journal npj Vaccines, a
common vaccine for tuberculosis (the Bacillus Calmette-Guérrin, or
BCG, vaccine) could improve type 1 diabetes by permanently lowering
blood sugar levels.
Lead researcher Dr Denise Faustman and her team examined data on
282 individuals, 52 of whom had type 1 diabetes and participated in
the BCG clinical trials and 230 of whom contributed blood
Those participating in the clinical trials (average duration of
their diabetes was 19 years) were given the vaccine twice four
weeks apart and then studied for about eight years following
Regular monitoring throughout the eight-year study found the
HbA1c levels of individuals receiving the vaccine dropped by more
than 10 per cent at the three-year mark and by more than 18 per
cent after four years of treatment. These levels reached
near-normal figures five years after treatment.
HbA1c refers to glycated haemoglobin, which develops when
haemoglobin, the red blood cell protein that carries oxygen
throughout the body, is combined with glucose in the blood.
Participants treated with BCG were found to have an average
HbA1C of 6.65 per cent four years later. The threshold for
diabetes diagnosis is on average close to an HbA1c of 6.5 per
Tuesday's ADA and JDRF statement urged caution:
"While this work has attracted attention, the study only
followed a very small number of patients - nine people at the
five-year time point, and three people at the eight-year time point
- and must be interpreted with caution.
Overall, the findings prompt through-provoking questions but not
definitive answers, and do not provide enough clinical evidence to
support any recommended change in therapy at this time.
Specific limitations that should be considered include:
- All study participants continued to use standard insulin
therapy throughout the trial; it's not a situation whereby the
treatment changed their standard of care (all vaccinated
individuals remained on insulin therapy).
- The patients with reported positive outcomes achieved only
moderately lower HbA1cs, which, while marginally statistically
significant, cannot be generalized to the millions of people living
with t1d and is not established to be as a result of the
- The article doesn't account for the natural variability in
HbA1c levels over time, which is well known to occur in this
population: they tend to improve in people with t1d as they age,
particularly as they move out of their teens and early 20s. It's
unclear what role natural history may have played in these
- There is no detail on the standard of care in the BCG treated
and control group. For example, was the care comparable between
both study groups or were adjunctive therapies used?"
Diabetes Queensland is presenting this information to readers as
a clear example of research that is faithfully presented to
scientific communities being reported by mainstream media without
the time, space or expertise to hedge research findings.
This organisation's commitment to you is to present the latest
information and work with all organisations to achieve a cure for
diabetes. We will continue to report all research news, but we urge
readers not to invest false hope in generic news.
When a cure for diabetes is announced, we promise to be on the
front foot to let you know about it. In the meantime, the research
and the hunt continues.