After an exhaustive review of over 1,000 research studies, a federal panel of experts in the United States has unequivocally stated that vaccines cause very few side effects and have found no evidence linking vaccines to autism or type 1 diabetes.
The report, released by the Institute of Medicine, a division of the National Academies of Sciences, represents the most comprehensive analysis of vaccine side effects since 1994.
Concerns regarding the potential adverse effects of vaccines, such as autism or other health issues, have led some parents to opt out of vaccinating their children, despite repeated assurances from health authorities. These concerns have also prompted costly adjustments to many vaccine formulations.
Chairing the committee, Ellen Wright Clayton, a professor of pediatrics and law, as well as the director of the Center for Biomedical Ethics and Society at Vanderbilt University in Nashville, emphasized the thoroughness of the review. “We scrutinized over 1,000 articles examining both the epidemiological and biological evidence regarding vaccine side effects,” she stated in an interview. “The primary takeaway is that we identified only a few instances where vaccines may cause adverse effects, and the vast majority of these are short-term and self-limiting.”
Commissioned by the U.S. Department of Health and Human Services, the report evaluated eight commonly administered vaccines, including MMR, DTaP, varicella (chickenpox), influenza, hepatitis B, meningococcal, tetanus-containing vaccines, and the human papillomavirus (HPV) vaccine. These vaccines provide protection against a range of diseases, encompassing measles, mumps, whooping cough, hepatitis, diphtheria, tetanus, chickenpox, meningitis, pneumococcal disease, and cervical cancer.
Regarding side effects, Clayton underscored that the MMR vaccine does not induce autism or type 1 diabetes. “The DTaP vaccine, which includes pertussis, does not lead to type 1 diabetes, and the inactivated flu vaccine does not cause Bell’s palsy or exacerbate asthma,” she added. “The evidence strongly refutes claims of these side effects being associated with vaccines.”
While vaccines may induce certain side effects, the majority are short-lived. For instance, the MMR vaccine might trigger seizures in individuals experiencing high fevers post-vaccination, but these seizures are transient and do not portend long-term harm. Additionally, the varicella vaccine may prompt adverse reactions such as brain swelling, pneumonia, hepatitis, meningitis, or shingles, predominantly in individuals with compromised immune systems.
Six vaccines—MMR, varicella, influenza, hepatitis B, meningococcal, and tetanus-containing vaccines—can potentially elicit anaphylaxis, an allergic reaction occurring shortly after administration. However, Clayton reassured that this risk can be mitigated by mandating patients to remain under observation for 15 minutes post-vaccination to monitor for allergic reactions.
In conclusion, Clayton emphasized that the report should alleviate concerns among many individuals regarding vaccine safety. “Despite exhaustive examination, it was challenging to identify instances where vaccines cause harm, and when they do, the effects are generally mild and transient,” she affirmed.