Thursday, October 22, 2015

Seasonal Flu Vaccine and Type-1 Diabetes

Every now and then I get asked about any safety issues for a flu vaccination for someone who has type-1 diabetes.  So I researched that question, and below is my summary of research to date.  Note that this summary focuses on flu vaccines only;  I have separate summaries for childhood vaccinations and also for HPV vaccinations.

I looked for all clinical trials where they gave flu vaccine to type-1 diabetics, specifically.  I did not think there would be any such studies, because recruiting from such a limited population would be tough.  But I was wrong.  There were several, but I only had time to look at the first 8 (listed below); some studies covered more than one area:
  • Two studies focused on safety, and these found no added risk to type-1 diabetics.
  • Four studies focused on effectiveness, and three of these found no differences in effectiveness between type-1 diabetics and the general population.  One study found that flu vaccines were less effective for type-1 diabetics as compared to the general population.
  • Three studies focus on flu vaccines affecting the immune system in a way which would contribute to type-1 diabetes, and these found that it did not.
Rather than summarize each study, I'm letting each study "speak for itself" by quoting the abstract from each one.  You can click on the abstract to see the exact study design: most were intervention studies with control groups; one was a population registry study.
One injection of 2009 pandemic influenza A(H1N1) MF59-adjuvanted vaccine is immunogenic and safe in young patients with Type 1 diabetes who are at increased risk of influenza morbidities. Pandemic vaccine can be safely co-administered with seasonal influenza vaccine.
The results indicate that in older children and young adults with type I diabetes influenza vaccination with a virosomal or a standard subunit vaccine is safe and adequately immunogenic against the three influenza vaccine strains. In addition, the virosomal vaccine may show better long-lasting immune response than the standard subunit vaccine, especially in subjects without pre-existing antibodies to influenza strains.
From these results it is concluded that IAA [an autoantibody linked to type-1 diabetes] formation is not a direct sequela of viral infection or vaccination.
Use of Pneumo 23 vaccine or its combination with Grippol vaccine in patients with DM1 did not result in increase of levels of autoantibodies to n-DNA, d-DNA and pancreatic tissue, was not able to initiate or lead to disease progression as well as positively influenced on the immune response with tendency to normalization of the several arms of the immune system and, at the same time, did not result in activation of autoimmune process.
No significant difference was found between diabetic patients and control subjects with respect to antibody response after vaccination.
The influenza-specific antibody response in both serum and oral fluid were similar for both groups, and also showing a kinetic profile in accordance with our earlier data for healthy adults. Our study did not detect a difference in the humoral immune response between juvenile diabetics and healthy controls.
Risks for Guillain-Barré syndrome, multiple sclerosis, type 1 diabetes, and rheumatoid arthritis remained unchanged.
In Type 1 (insulin-dependent) diabetic patients the incidence of non-responders to two vaccine components was significantly increased
Taken together, these studies show that flu vaccines are safe for type-1 diabetics, do not worsen the immunology behind type-1 diabetes, and are effective for type-1 diabetics. One one study found that flu vaccines were less effective for type-1 diabetics than for the general population, but less effective does not mean "not effective"!

Joshua Levy 
publicjoshualevy at gmail dot com 
All the views expressed here are those of Joshua Levy, and nothing here is official JDRF or JDCA news, views, policies or opinions. My daughter has type-1 diabetes and participates in clinical trials, which might be discussed here. My blog contains a more complete non-conflict of interest statement. Thanks to everyone who helps with the blog.