This story from STAT met most of our criteria in describing the results of a study that examined how two doses of the generic bacillus Calmette Guérin (BCG) vaccine, used for nearly a century against tuberculosis, affected blood sugar levels Type 1 diabetics. We were especially glad to see the results given in absolute numbers and that it emphasized how small the study was.
However, we did want to note that we think the story didn’t provide enough evidence to back the researcher’s claim that her research hasn’t been given much attention because she is pursuing a “low-tech” diabetes treatment with little potential for generating profit. This may well be true, but we should have heard from more sources other than the researcher and received more historical context to support the claim. We also urge caution around the use of “controversial” to describe medical science.
Note: We also reviewed a news release on this research, which focuses on a larger group of 52 patients who haven’t been followed as long as the 9 subjects reported on here.
According to the American Diabetes Association, about 1.25 million Americans have Type 1 diabetes, an autoimmune disease in which the pancreas stops producing insulin. Scientists do not know what causes Type 1 diabetes, and management of the disease requires monitoring blood sugar levels at least six times daily, along with careful monitoring of diet and exercise. However, maintaining the right insulin level is tricky, even with the implanted glucose monitors and insulin pumps commonly used among Type 1 diabetics. Complications include damage to the heart and blood vessels, nerves, kidneys, eyes, and feet, potentially leading to kidney failure, amputations and even death. A 2016 Business Insider story estimated that managing the disease can cost Type 1 diabetics more than $1,000 a month. A low-cost, safe intervention such as a well-established vaccine would be a big improvement, but news stories must be careful to convey that this research is still experimental.
The story notes that the BCG vaccine costs less than $1 per dose, though it remains to be seen if the cost will remain the same if it’s approved for diabetes. The story does acknowledge that treatment with the BCG vaccine did not eliminate the study patients’ need for insulin.
Wisely, the story quantifies reduction in absolute terms: “In the vaccinated patients, A1c levels fell from an average of 7.36 before the first dose to 6.18 after five years, holding almost steady at 6.65 in the eighth year. In patients receiving a sham injection, levels showed almost no change from their initial levels of 7.10: 7.07 in the fifth year and 7.22 in the eighth.”
The story also explains exactly how much the drop in hemoglobin A1c was (9-16%) and how that compared to the levels in patients receiving the placebo injections and to normal A1c levels. The story also noted that a 10% drop in A1c levels reduces the likelihood of complications such as stroke and heart attack by a third. In addition, the story explained that the patients treated with the BCG vaccine now need one-third less insulin than they did before the treatment, “reducing their risk of hypoglycemia, in which insulin lowers blood sugar to dangerously low levels.” One relatively minor shortcoming is that the story did not explain that the reduction in hemoglobin A1c levels didn’t occur until the third year after the vaccinations had been given.
The story notes that the BCG vaccine, an attenuated form of Mycobacterium bovis that has been used to treat tuberculosis for nearly 100 years, is considered extremely safe.
There are some rare side effects of the BCG vaccine (as for any medicine), so the article could have mentioned this, though.
The story notes in the headline that it’s a small study and explains that the study involved only nine patients. However, it also notes that these patients were followed up for five to eight years and that there was a placebo control group (of three patients). It also notes that 111 additional patients have received the vaccine more recently, though the study’s follow-up data did not include this larger group.
There is no disease-mongering in the story.
The original journal article on which this story was based includes the researchers’ declaration that they had no conflict of interest. The story includes two sources who were not involved in the research, although one of these sources, a researcher from Radboud University Medical Center in the Netherlands, cannot be considered fully independent, because the quote appears to have been copied from a Massachusetts General Hospital news release about the study (see news release criterion, below).
The story also noted that two diabetes research centers and “several university diabetes centers all declined to speak about Faustman’s results.” This hints at the “controversy” noted in the headline, around the possibility of conflicts of interest that can occur when pharma-supported researchers/advocacy groups criticize this type of research. But the story didn’t explore this sufficiently to prove the researcher’s claim that funders aren’t interested because it has low profit potential, as noted in the summary.
The only alternative is insulin, and the story makes clear that even with the vaccine, patients still need to take it, but in smaller doses.
The story does not explicitly address the issue of when, if ever, patients might have access to the BCG vaccine as a treatment for Type 1 diabetes. However, it does state that the treatment is being tested in a Phase 2 clinical trial involving 150 patients with Type 1 diabetes. The story also notes that one barrier to further development of BCG as a diabetes treatment is that it would appear to have little commercial value, meaning that drug manufacturers aren’t interested in it.
The story notes that generic BCG vaccine has been used for nearly 100 years to treat tuberculosis and that it has been studied in other countries worldwide for its effects on diabetes, multiple sclerosis and other autoimmune diseases.
One of the quotes included from a researcher not involved in the study does appear to have been taken from a Massachusetts General Hospital news release, and that is not noted in the story. We also reviewed the news release. If that connection had been disclosed, this would have been satisfactory.