This informal CPD article ‘Type 1 Diabetes and Vaccines: What Parents Need to Know’ was provided by Cima Care, who offer extensive training in vaccination and public health, advancing global health initiatives.
Recent research is delivering clearer insights into the relationship between vaccines and Type 1 diabetes, with some findings that may come as a surprise. When Sarah's 6-year-old daughter, Emma, was diagnosed with Type 1 diabetes, one of her major concerns was whether vaccines had played a role. Like many parents, she had heard different thoughts and wanted to understand the truth. Research on this topic displays essential information that every parent should be aware of.
Understanding Type 1 Diabetes
Type 1 diabetes is an autoimmune disorder in which the body's immune system wrongly attacks the cells in the pancreas that produce insulin. Unlike Type 2 diabetes, which is often related to lifestyle factors, Type 1 diabetes typically develops in children and young adults and is not preventable through diet or exercise.
This condition has been increasing worldwide over recent decades. Nordic countries like Finland now see over 60 new cases per 100,000 children each year—the highest rates globally—while Asian and African populations have much lower rates.1, 2 & 3 This difference suggests that both genetics and environmental factors play important roles.
Scientists now understand that Type 1 diabetes develops in three stages:
- Stage 1: Certain antibodies appear in the blood, but blood sugar stays normal.
- Stage 2: The immune system continues its attack, and blood sugar levels begin to change.
- Stage 3: Full diabetes develops with symptoms that need insulin treatment.
Early detection during Stages 1 or 2 may help prevent serious complications and preserve remaining insulin production.4
What Research Shows About Vaccines and Type 1 Diabetes
The largest study on this issue observed 739,694 children in Denmark over several years. Researchers tracked these children as they received their routine vaccines and monitored their health consequences. The study found no connection between childhood vaccines and increased risk of Type 1 diabetes. 6
Multiple further investigations involving millions of children worldwide have confirmed this finding. The scientific evidence consistently shows that vaccines do not cause Type 1 diabetes. 7 & 8 However, a 2021 study notes that the immune response to vaccines may be less robust in patients with type 1 diabetes due to underlying immune dysregulation, potentially reducing the vaccine’s clinical effectiveness. 5
Rotavirus Vaccine: A Potential Protective Effect
Recent research has revealed an unexpected finding about the rotavirus vaccine, which protects against a virus that causes severe diarrhoea in young children. A study analysing data from 4.4 million children across several developed countries found that those who received the rotavirus vaccine had a 13% lower risk of developing type 1 diabetes compared to those who were unvaccinated.9
In Australia, following the introduction of the rotavirus vaccine in 2007, rates of Type 1 diabetes in young children (ages 0-4) decreased by 13% for the first time since the 1980s. Older children (5–14 years) showed no such reduction in Type 1 diabetes, suggesting that the vaccine's protective effect is specific to early childhood exposures. 10
How This Protection Might Work
Scientists believe this protection may be related to a process called "molecular mimicry". When children become infected with natural rotavirus, certain parts of the virus are similar to parts of pancreatic cells. This similarity can sometimes confuse the immune system, causing it to attack both the virus and pancreatic cells.
By preventing rotavirus infection through vaccination, this immune confusion may be avoided, potentially protecting some children from developing Type 1 diabetes.11&12
BCG vaccination showed refinements in blood sugar
BCG Vaccine: New Uses for an Old Vaccine
The BCG vaccine, originally developed in the 1920s to prevent tuberculosis, is now being studied as a potential treatment for people who already have Type 1 diabetes.
In recent clinical studies, individuals with Type 1 diabetes who received BCG vaccination showed refinements in blood sugar control, with average levels declining by 10% and remaining lower for up to 8 years. 13, 14, & 15 During the COVID-19 pandemic, studies in 2024 showed that individuals who had received BCG were also less likely to develop serious infections from COVID-19 and other infections, with protective effects lasting nearly the entire pandemic period. ¹⁶
The BCG vaccine appears to work by changing how immune cells process glucose, particularly in the spleen, which helps remove excess glucose from the bloodstream. 14 & 15
Practical Guidance for Families
For families dealing with Type 1 diabetes, current research provides clear guidance:
- Vaccines are safe and important. Children with diabetes have a higher risk of serious complications from infections that vaccines can prevent. They are three times more likely to die and six times more likely to be hospitalised due to flu-related complications compared to children without diabetes.17 & 5
- All routine childhood vaccines should be given on schedule. The standard vaccination schedule is safe for children with Type 1 diabetes and provides important protection against serious diseases.5
- Monitor blood sugar on vaccination days. Like any immune response, vaccines can temporarily affect blood sugar levels. Parents should check glucose levels more frequently on vaccination days and adjust insulin to maintain the required control. 18
Current Research Directions
Scientists continue to investigate whether the protective effects of rotavirus vaccination are applicable to children in various parts of the world. Research on BCG vaccination is exploring the best dosing strategies and identifying which patients benefit most from this treatment. 16
These studies represent significant progress in understanding how vaccines interact with autoimmune diseases, such as Type 1 diabetes.
Key Takeaways
Scientific evidence clearly demonstrates that routine childhood vaccinations do not cause Type 1 diabetes. In fact, some vaccines may even offer protection against developing the condition; however, further research is required to fully understand these effects.
For families affected by Type 1 diabetes, vaccines remain an important tool for safeguarding health and may even present therapeutic benefits in the future.
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REFERENCES
1- Mittal R, Camick N, Lemos JR, Hirani K. Gene-environment interaction in the pathophysiology of type 1 diabetes. Frontiers in Endocrinology. 2024 Jan 26;15:1335435.
2- New Type 1 Diabetes Statistics Report [Internet]. Type1strong.org. 2025. Available from: https://www.type1strong.org/blog-post/new-type-1-diabetes-statistics-report.
3- Gong B, Yang W, Xing Y, Lai Y, Shan Z. Global, regional, and national burden of type 1 diabetes in adolescents and young adults. Pediatric Research. 2024 Mar 5:1-9.
4- Type 1 diabetes staging classification opens door for intervention | TRIALNET Type 1 Diabetes TrialNet [Internet]. www.trialnet.org.
5- Esposito S, Mariotti Zani E, Torelli L, Scavone S, Petraroli M, Patianna V, Predieri B, Iughetti L, Principi N. Childhood vaccinations and type 1 diabetes. Frontiers in Immunology. 2021 Aug 26;12:667889.
6- DeStefano F, Mullooly JP, Okoro CA, Chen RT, Marcy SM, Ward JI, Vadheim CM, Black SB, Shinefield HR, Davis RL, Bohlke K. Childhood vaccinations, vaccination timing, and risk of type 1 diabetes mellitus. Pediatrics. 2001 Dec 1;108(6):e112-.
7- Glanz JM, Clarke CL, Daley MF, Shoup JA, Hambidge SJ, Williams JT, Groom HC, Kharbanda EO, Klein NP, Jackson LA, Lewin BJ. The childhood vaccination schedule and the lack of association with type 1 diabetes. Pediatrics. 2021 Dec 1;148(6).
8- The. Vaccines and Diabetes [Internet]. Chop.edu. 2019. Available from: https://www.chop.edu/vaccine-education-center/vaccine-safety/vaccines-and-other-conditions/diabetes.
9- Kosmeri C, Klapas A, Evripidou N, Kantza E, Serbis A, Siomou E, Ladomenou F. Rotavirus Vaccination Protects Against Diabetes Mellitus Type 1 in Children in Developed Countries: A Systematic Review and Meta-Analysis. Vaccines. 2025 Jan 9;13(1):50.
10- Harrison PL. Possible link between rotavirus vaccine and decline in type 1 diabetes [Internet]. WEHI. 2019 [cited 2025 May 5]. Available from: https://www.wehi.edu.au/news/possible-link-between-rotavirus-vaccine-and-decline-type-1-diabetes/
11- Rogers MA, Basu T, Kim C. Lower incidence rate of type 1 diabetes after receipt of the rotavirus vaccine in the United States, 2001-2017. Sci Rep 9 (1): 7727 [Internet]. 2019
12- Suliman BA. Potential clinical implications of molecular mimicry‐induced autoimmunity. Immunity, Inflammation and Disease. 2024 Feb;12(2):e1178.
13- Century-old Vaccine Protects Type 1 Diabetics from Infectious Diseases [Internet]. Massachusetts General Hospital. 2024. Available from: https://www.massgeneral.org/news/press-release/century-old-vaccine-protects-type-1-diabetics.
14- Iliyah. Dr Denise Faustman | An Unexpected Ally in the Fight Against Diabetes: The BCG Vaccine • scientia.global [Internet]. scientia.global. 2025. Available from: https://www.scientia.global/dr-denise-faustman-an-unexpected-ally-in-the-fight-against-diabetes-the-bcg-vaccine/
15- Dias HF, Fu JF, Luck TG, Wolfe GE, Hostetter ER, Ng NC, Zheng H, Kühtreiber WM, Price JC, Catana C, Faustman DL. The spleen assumes a major role in blood glucose regulation in type 1 diabetes patients treated with BCG. Scientific Reports. 2024 Jul 30;14(1):17611.
16- New Purpose [Internet]. Harvard.edu. 2018 [cited 2025 May 5]. Available from: https://hms.harvard.edu/news/new-purpose
17- For People With Diabetes, Flu Vaccination is More Important Than Ever - NFID [Internet]. https://www.nfid.org/. Available from: https://www.nfid.org/for-people-with-diabetes-flu-vaccination-is-more-important-than-ever/
18- Al-Ozairi E, Irshad M, Taghadom E, Varghese A, Sojan L, Alkandari J. Effect of COVID-19 vaccine on blood glucose metrics in Arabic people with type 1 diabetes. Frontiers in Endocrinology. 2023 Mar 20;14:1120384.
