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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.

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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. Vaccines
  3. Measles, Mumps & Rubella (MMR II)
  4. 1991
Measles, Mumps & Rubella (MMR II)1991

Measles, Mumps & Rubella (MMR II) in 1991

2,143 adverse event reports (+840% vs 1990)

Share
2,143
Reports
10
Deaths
226
Hospitalizations
975
ER Visits
23
Disabilities
← 1990 (228 reports)1992 (2,134 reports) →

1991 Reporting Summary

In 1991, 2,143 adverse event reports were filed for Measles, Mumps & Rubella (MMR II) in VAERS. This represents 2.4% of all 89,976 reports for this vaccine.

Of these reports, 10 mentioned death, 226 involved hospitalization, 975 required ER visits, and 23 reported disability.

Compared to the average of 2,391 reports per year for this vaccine, 1991 was below average (-10%).

💡 What This Means

Year-over-year change: The large change from 1990 likely reflects a ramp-up in vaccination (e.g., new vaccine rollout or expanded eligibility) rather than a change in per-dose risk.

All Years for Measles, Mumps & Rubella (MMR II)

YearReportsDeathsHosp.
20251,629360
20241,5711240
20231,362335
20221,385230
20211,431546
20201,205555
20192,526893
20181,787357
20172,514280
20162,744781
20153,1621585
20142,502283
20132,231374
20122,35312113
20112,51311138
20103,1485144
20093,14530159
20083,24811134
20072,2758105
20063,47915161
20053,78510159
20044,1787165
20034,15810166
20023,6049161
20013,08316189
20002,47010155
19992,16718163
19981,9269151
19972,06412176
19962,00412182
19952,06611219
19942,05311218
19931,80313188
19922,13417211
1991 ← current2,14310226
1990228544

Understanding Yearly Data

•Spikes may reflect awareness: Years with unusual activity (e.g., pandemic) often see increased reporting.
•Dose volume matters: More vaccinations given in a year naturally leads to more reports.
•Reporting lag: Some events are reported months after they occur, so recent years may be incomplete.

Quick Facts

Reports:2,143
Deaths:10
Hospitalizations:226
% of Total:2.4%
Rank (by vol.):#21 of 36 years
Avg/year:2,391

Related Pages

Measles, Mumps & Rubella (MMR II) Overview← 1990 Reports1992 Reports →35 Years of ReportingCompare Vaccines

Data Source

This data comes from the Vaccine Adverse Event Reporting System (VAERS), jointly managed by CDC and FDA.