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Data source: VAERS (Vaccine Adverse Event Reporting System)

Data through 2026 · Updated quarterly

Built by TheDataProject.ai · © 2026 VaccineWatch

Important: VAERS accepts reports of adverse events following vaccination. For any given report, there is no certainty that the reported event was caused by the vaccine. Reports may contain information that is incomplete, inaccurate, coincidental, or unverifiable. Most reports to VAERS are voluntary, which means they are subject to biases. This data cannot be used to determine if vaccines cause or contribute to adverse events.

⚠️

Important: VAERS reports alone cannot determine if a vaccine caused an adverse event. Reports may contain incomplete, inaccurate, or unverified information. Correlation does not equal causation.

  1. Home
  2. Vaccine Side Effects
  3. MMR Vaccine
7 min read
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MMR Vaccine Side Effects

The MMR (measles, mumps, rubella) vaccine is one of the most widely studied vaccines in history. Given to virtually every child in the U.S., it generates a substantial number of VAERS reports — but context is essential for interpreting this data.

113,538
Total Reports
542
Deaths Reported
5,685
Hospitalizations
36,986
ER Visits

Most Commonly Reported Side Effects

The following symptoms are most frequently reported after vaccination:

#{i + 1}Pyrexia
23,873
#{i + 1}Rash
13,811
#{i + 1}Injection site erythema
12,059
#{i + 1}No adverse event
8,580
#{i + 1}Erythema
6,579
#{i + 1}Injection site swelling
6,533
#{i + 1}Urticaria
5,891
#{i + 1}Pruritus
5,176
#{i + 1}Injection site oedema
4,926
#{i + 1}Injection site warmth
4,639
#{i + 1}Vomiting
4,559
#{i + 1}Injection site pain
4,541

MMR and Autism: The Data

The claimed link between MMR and autism has been extensively studied and debunked. The original 1998 study was retracted and its author lost his medical license for fraud. Multiple large-scale studies involving millions of children have found no connection between MMR vaccination and autism.

VAERS does contain reports mentioning autism after MMR vaccination, but VAERS reports are unverified and cannot establish causation. The timing of MMR vaccination (12-15 months) coincides with when autism symptoms typically become noticeable, creating a temporal correlation that is not causal.

Expected Side Effects

Common (usually mild, resolve in days):

  • Fever (up to 1 in 6 children)
  • Mild rash
  • Swelling of glands in cheeks or neck
  • Soreness and redness at injection site
  • Joint pain/stiffness (more common in adult women)

Rare but serious:

  • Febrile seizures (about 1 in 3,000)
  • Temporary low platelet count (about 1 in 25,000)
  • Allergic reaction (very rare)
⚠️ Remember: VAERS reports show correlation, not causation. A report filed after vaccination doesn't mean the vaccine caused the reported event. Always consult your healthcare provider for medical advice.

Explore This Data

MMR Vaccine Detail Page →
Full VAERS profile with charts
Pediatric Analysis →
Childhood vaccine patterns
COVID Vaccine Side Effects →
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