Do Vaccines Cause Autism?

Updated July 12, 2023



Natural infection with influenza can contribute to asthma exacerbation. Thus, influenza vaccine prevents asthma exacerbation by protecting against natural infection. Influenza vaccines do not cause asthma or asthma exacerbation. Other vaccines currently routinely recommended to the general population in the U.S.* have not been shown to cause asthma or asthma exacerbation. Aluminum adjuvants in vaccines have not been shown to cause asthma in children.

Epidemiological evidence

The 2012 report on adverse effects of vaccines by the Institute of Medicine (IOM) 1, now called the National Academy of Medicine (NAM), described a number of studies with sufficient validity and precision that all found no association between inactivated influenza vaccination and asthma exacerbation 2-10. The report described several studies with sufficient validity and precision that generally reported no association between live attenuated influenza vaccination (LAIV) and asthma exacerbation as well 11-17.

A 2015 white paper on the safety of influenza vaccines concluded that LAIV was associated with an increase in wheezing in children ages 18 to 35 months who had a history of wheezing; though in the U.S. LAIV is not approved for children under 2 years of age and “should not be used” in children 2-4 years of age with a history of wheezing or asthma in the previous year 18. Two studies of the 2013-2014 and 2014-2015 flu seasons in the United Kingdom study found that LAIV was well tolerated among those with well-controlled asthma or recurrent wheezing 19,20. A prospective observational cohort study found an increased risk of wheezing among California children 2-4 years of age during the 42-day risk interval after receiving quadrivalent LAIV during the 2013–2014 influenza season 21.

Analysis of a survey of 1875 primary school children in the Netherlands found no association between receiving DTP-IPV vaccine and asthma or other atopic disorders (e.g., hay fever, eczema, food allergy) 22. A nested case-control study of Dutch and German children found no relationship between vaccination against pertussis, measles, rubella, or Hib and atopic disease or respiratory symptoms 23. A self-controlled case series of US infants born prematurely found no increased risk of wheezing lower respiratory diseases associated with DTaP, IPV, Hib, varicella, PCV7, MMR, or TIV vaccination (and live attenuated vaccinations even seemed to provide a temporary protective effect) 24. An Australian cohort study found a reduced risk of asthma (at 6 years of age) among children who received OPV (RR: 0.60; 95%CI:0.37-0.98) and an increased risk of asthma among children who received diphtheria-tetanus vaccines (not currently used in the US) (RR 1.76; 95%CI 1.11-2.78); associations were not found for other vaccinations routinely administered in the first two years of life 25.  

One study published in 2015 suggests a possible protective effect of MMR vaccination against asthma 26. A 2002 Vaccine Safety Datalink (VSD) study did not find an association between asthma and diphtheria, tetanus and whole cell pertussis vaccine (relative risk: 0.92; 95% confidence interval: 0.83-1.02), oral polio vaccine (RR: 1.09; 95% CI: 0.90-1.23), or measles mumps and rubella (MMR) vaccine (RR: 0.97; 95% CI: 0.91-1.04); weak associations were found with Haemophilus influenzae type b (Hib) vaccine (RR: 1.18; 95% CI: 1.02-1.36) and hepatitis B vaccine (RR:1.20; 95% CI: 1.13-1.27) 27. A 2022 VSD study found an association between aluminum adjuvanted vaccines and persistent asthma among both children with eczema (adjusted hazard ratio: 1.26 per 1 mg increase in aluminum; 95% CI: 1.07-1.49) and children without eczema (aHR 1.19; 95% CI: 1.14-1.25). However, these limited observational data are insufficient to draw clear causal conclusions 28.

Proposed biological mechanism

Influenza, along with other natural viral respiratory infections, can contribute to asthma exacerbation, as these viruses enter and replicate within airway epithelial cells, causing damage and initiating an immune response. Natural influenza infection also causes greater morbidity in asthmatic subjects than in the general population, perhaps due to a difference in the antiviral response of asthmatics 29.

The 2012 IOM report described cases of asthma exacerbation after both inactivated and live attenuated influenza vaccination 30; however, even after considering knowledge about the aforementioned natural infection, the IOM concluded that this mechanistic evidence was weak 1.

Animal studies suggest that aluminum adjuvants could impact allergy risk through inducing a T helper 2 cell (Th2) immune response 31,32. In allergic asthma, Th2 lymphocytes mediate airway inflammation and hyper-responsiveness 33. Exposure to aluminum through vaccination could bias the immune profile toward Th2 immune responses, thus theoretically increasing risk of allergic diseases such as asthma 28.

* These conclusions do not necessarily consider vaccines recommended only for special populations in the United States such as Yellow Fever vaccine (international travelers) or Smallpox vaccine (military personnel).


1.         Institute of Medicine. In: Stratton K, Ford A, Rusch E, Clayton EW, eds. Adverse Effects of Vaccines: Evidence and Causality. Washington (DC): National Academies Press (US); 2012.

2.         The safety of inactivated influenza vaccine in adults and children with asthma. The New England journal of medicine 2001;345(21):1529-36. (In eng). DOI: 10.1056/NEJMoa011961.

3.         Bueving HJ, Bernsen RM, de Jongste JC, et al. Does influenza vaccination exacerbate asthma in children? Vaccine 2004;23(1):91-6. (In eng). DOI: 10.1016/j.vaccine.2004.03.067.

4.         France EK, Glanz JM, Xu S, et al. Safety of the trivalent inactivated influenza vaccine among children: a population-based study. Archives of pediatrics & adolescent medicine 2004;158(11):1031-6. (In eng). DOI: 10.1001/archpedi.158.11.1031.

5.         Hambidge SJ, Glanz JM, France EK, et al. Safety of trivalent inactivated influenza vaccine in children 6 to 23 months old. Jama 2006;296(16):1990-7. (In eng). DOI: 10.1001/jama.296.16.1990.

6.         Kmiecik T, Arnoux S, Kobryn A, Gorski P. Influenza vaccination in adults with asthma: safety of an inactivated trivalent influenza vaccine. J Asthma 2007;44(10):817-22. (In eng). DOI: 10.1080/02770900701539723.

7.         Nicholson KG, Nguyen-Van-Tam JS, Ahmed AH, et al. Randomised placebo-controlled crossover trial on effect of inactivated influenza vaccine on pulmonary function in asthma. Lancet 1998;351(9099):326-31. (In eng). DOI: 10.1016/s0140-6736(97)07468-0.

8.         Pedroza A, Huerta JG, Garcia Mde L, et al. The safety and immunogenicity of influenza vaccine in children with asthma in Mexico. Int J Infect Dis 2009;13(4):469-75. (In eng). DOI: 10.1016/j.ijid.2008.08.015.

9.         Stenius-Aarniala B, Huttunen JK, Pyhala R, et al. Lack of clinical exacerbations in adults with chronic asthma after immunization with killed influenza virus. Chest 1986;89(6):786-9. (In eng).

10.       Tata LJ, West J, Harrison T, Farrington P, Smith C, Hubbard R. Does influenza vaccination increase consultations, corticosteroid prescriptions, or exacerbations in subjects with asthma or chronic obstructive pulmonary disease? Thorax 2003;58(10):835-9. (In eng).

11.       Ashkenazi S, Vertruyen A, Aristegui J, et al. Superior relative efficacy of live attenuated influenza vaccine compared with inactivated influenza vaccine in young children with recurrent respiratory tract infections. The Pediatric infectious disease journal 2006;25(10):870-9. (In eng). DOI: 10.1097/01.inf.0000237829.66310.85.

12.       Belshe RB, Edwards KM, Vesikari T, et al. Live attenuated versus inactivated influenza vaccine in infants and young children. The New England journal of medicine 2007;356(7):685-96. (In eng). DOI: 10.1056/NEJMoa065368.

13.       Belshe RB, Nichol KL, Black SB, et al. Safety, efficacy, and effectiveness of live, attenuated, cold-adapted influenza vaccine in an indicated population aged 5-49 years. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2004;39(7):920-7. (In eng). DOI: 10.1086/423001.

14.       Bergen R, Black S, Shinefield H, et al. Safety of cold-adapted live attenuated influenza vaccine in a large cohort of children and adolescents. The Pediatric infectious disease journal 2004;23(2):138-44. (In eng). DOI: 10.1097/01.inf.0000109392.96411.4f.

15.       Gaglani MJ, Piedra PA, Riggs M, Herschler G, Fewlass C, Glezen WP. Safety of the intranasal, trivalent, live attenuated influenza vaccine (LAIV) in children with intermittent wheezing in an open-label field trial. The Pediatric infectious disease journal 2008;27(5):444-52. (In eng). DOI: 10.1097/INF.0b013e3181660c2e.

16.       Piedra PA, Gaglani MJ, Riggs M, et al. Live attenuated influenza vaccine, trivalent, is safe in healthy children 18 months to 4 years, 5 to 9 years, and 10 to 18 years of age in a community-based, nonrandomized, open-label trial. Pediatrics 2005;116(3):e397-407. (In eng). DOI: 10.1542/peds.2004-2258.

17.       Fleming DM, Crovari P, Wahn U, et al. Comparison of the efficacy and safety of live attenuated cold-adapted influenza vaccine, trivalent, with trivalent inactivated influenza virus vaccine in children and adolescents with asthma. The Pediatric infectious disease journal 2006;25(10):860-9. (In eng). DOI: 10.1097/

18.       Halsey NA, Talaat KR, Greenbaum A, et al. The safety of influenza vaccines in children: An Institute for Vaccine Safety white paper. Vaccine 2015;33 Suppl 5:F1-f67. (In eng). DOI: 10.1016/j.vaccine.2015.10.080.

19.       Turner PJ, Southern J, Andrews NJ, Miller E, Erlewyn-Lajeunesse M. Safety of live attenuated influenza vaccine in young people with egg allergy: multicentre prospective cohort study. BMJ (Clinical research ed) 2015;351:h6291. (In eng). DOI: 10.1136/bmj.h6291.

20.       Turner PJ, Southern J, Andrews NJ, Miller E, Erlewyn-Lajeunesse M. Safety of live attenuated influenza vaccine in atopic children with egg allergy. The Journal of allergy and clinical immunology 2015;136(2):376-81. (In eng). DOI: 10.1016/j.jaci.2014.12.1925.

21.       Baxter R, Eaton A, Hansen J, Aukes L, Caspard H, Ambrose CS. Safety of quadrivalent live attenuated influenza vaccine in subjects aged 2-49years. Vaccine 2017;35(9):1254-1258. (In eng). DOI: 10.1016/j.vaccine.2017.01.062.

22.       Bernsen RM, de Jongste JC, Koes BW, Aardoom HA, van der Wouden JC. Diphtheria tetanus pertussis poliomyelitis vaccination and reported atopic disorders in 8-12-year-old children. Vaccine 2006;24(12):2035-42. (In eng). DOI: 10.1016/j.vaccine.2005.10.056.

23.       Mommers M, Weishoff-Houben M, Swaen GM, et al. Infant immunization and the occurrence of atopic disease in Dutch and German children: a nested case-control study. Pediatric pulmonology 2004;38(4):329-34. (In eng). DOI: 10.1002/ppul.20089.

24.       Mullooly JP, Schuler R, Mesa J, Drew L, DeStefano F. Wheezing lower respiratory disease and vaccination of premature infants. Vaccine 2011;29(44):7611-7. (In eng). DOI: 10.1016/j.vaccine.2011.08.022.

25.       Thomson JA, Widjaja C, Darmaputra AA, et al. Early childhood infections and immunisation and the development of allergic disease in particular asthma in a high-risk cohort: A prospective study of allergy-prone children from birth to six years. Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology 2010;21(7):1076-85. (In eng). DOI: 10.1111/j.1399-3038.2010.01018.x.

26.       Timmermann CA, Osuna CE, Steuerwald U, Weihe P, Poulsen LK, Grandjean P. Asthma and allergy in children with and without prior measles, mumps, and rubella vaccination. Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology 2015;26(8):742-9. (In eng). DOI: 10.1111/pai.12391.

27.       DeStefano F, Gu D, Kramarz P, et al. Childhood vaccinations and risk of asthma. The Pediatric infectious disease journal 2002;21(6):498-504. (In eng). DOI: 10.1097/00006454-200206000-00004.

28.       Daley MF, Reifler LM, Glanz JM, et al. Association Between Aluminum Exposure From Vaccines Before Age 24 Months and Persistent Asthma at Age 24 to 59 Months. Acad Pediatr 2023;23(1):37-46. DOI: 10.1016/j.acap.2022.08.006.

29.       Jackson DJ, Johnston SL. The role of viruses in acute exacerbations of asthma. The Journal of allergy and clinical immunology 2010;125(6):1178-87; quiz 1188-9. (In eng). DOI: 10.1016/j.jaci.2010.04.021.

30.       de Jongste JC, Degenhart HJ, Neijens HJ, Duiverman EJ, Raatgeep HC, Kerrebijn KF. Bronchial responsiveness and leucocyte reactivity after influenza vaccine in asthmatic patients. Eur J Respir Dis 1984;65(3):196-200. (In eng).

31.       Hogenesch H. Mechanism of immunopotentiation and safety of aluminum adjuvants. Frontiers in immunology 2012;3:406. (In eng). DOI: 10.3389/fimmu.2012.00406.

32.       Sastry M, Zhang B, Chen M, et al. Adjuvants and the vaccine response to the DS-Cav1-stabilized fusion glycoprotein of respiratory syncytial virus. PloS one 2017;12(10):e0186854. (In eng). DOI: 10.1371/journal.pone.0186854.

33.       Robinson DS. The role of the T cell in asthma. The Journal of allergy and clinical immunology 2010;126(6):1081-91; quiz 1092-3. (In eng). DOI: 10.1016/j.jaci.2010.06.025.

Talking Points

Talking Points

 Step 1: Establish empathy and credibility
·         As your doctor, I know that you want to make the best choices about vaccines for you and your family.

·         I also know there is a lot of information out there, and it is difficult to figure out who to trust.

·         Would it be okay if I share with you what I have learned from my experience, and what I share with my patients, my family and my friends about autism?

Step 2: Briefly address specific concerns, if any
·         The idea that childhood vaccines cause autism is a myth. Childhood vaccines do not cause autism.

·         There have been 15 well conducted studies to see if childhood vaccines cause autism.  All of them have concluded that childhood vaccines do not cause autism.

·         MMR vaccine actually prevents congenital rubella syndrome and its associated cases of autism.

Step 3: Pivot to disease risk
·         Vaccine-preventable diseases are real and have very real dangers associated with them, including illness, and even death. They are also equal opportunity diseases, as they can infect anyone at any time.

·         Measles in particular is making a comeback in the United States and can cause inflammation of the brain, seizures, and death.

Step 4: Convey vaccine effectiveness
·         Vaccines are highly effective at protecting you and your family from vaccine-preventable diseases.

·         Over 99% of children who receive two doses of MMR develop immune protection against measles. The MMR vaccine is also over 90% effective against rubella, and over 66% effective against mumps.

Step 5: Give a strong and personalized recommendation
·         You and I have the same goal: to keep you and your family healthy.

·         You have the power to protect yourself and your family from these diseases through vaccination.

·         I strongly recommend vaccination to my patients, my family, and my friends.