Reported Reactions

Drugs

Brand name · Measles, mumps, and rubella virus vaccine live

M-M-R Ii: adverse event reports filed with FDA

862 reports list it as a suspect or interacting product, 2008–2026.

862
reports as suspect product
0% of all reports · about 48 a year
124
reports, 12 months to June 2026
74 in the 12 months before
10.7%
marked serious by the reporter
57.4% across all reports
0.7%
record death among outcomes, as reported
6 reports · not verified by FDA

862 adverse event reports received by FDA list the brand name M-M-R Ii (measles, mumps, and rubella virus vaccine live) as a suspect or interacting product, from June 2008 to June 2026. A further 77 reports list it only as a concomitant medication, and those are not counted in the figures on this page.

In the 12 months to June 2026, 124 reports listed it, up 68% from 74 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 48 reports a year and 0% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

The MedDRA terms listed most often are no adverse event (69.7%), product storage error (24.8%) and expired product administered (16.7%). A report can list several reactions, so shares add to more than 100%; 124 different terms appear across these reports. No adverse event is recorded in 69.7% of these reports, against 0.8% of all reports in the database.

10.7% of the reports are marked serious by the reporter; 0.7% record death among the outcomes and 2.9% record hospitalisation, as reported. 62.1% of the reports came from other health professionals, and the largest patient age group is under 2 (15.8%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

01325Jul 2021: 0Aug 2021: 1Sep 2021: 0Oct 2021: 4Nov 2021: 1Dec 2021: 52022Jan 2022: 0Feb 2022: 3Mar 2022: 4Apr 2022: 8May 2022: 6Jun 2022: 5Jul 2022: 3Aug 2022: 5Sep 2022: 5Oct 2022: 2Nov 2022: 0Dec 2022: 42023Jan 2023: 7Feb 2023: 8Mar 2023: 4Apr 2023: 2May 2023: 4Jun 2023: 3Jul 2023: 5Aug 2023: 5Sep 2023: 1Oct 2023: 1Nov 2023: 4Dec 2023: 42024Jan 2024: 0Feb 2024: 6Mar 2024: 2Apr 2024: 5May 2024: 0Jun 2024: 4Jul 2024: 3Aug 2024: 1Sep 2024: 2Oct 2024: 2Nov 2024: 3Dec 2024: 22025Jan 2025: 5Feb 2025: 6Mar 2025: 10Apr 2025: 11May 2025: 22Jun 2025: 7Jul 2025: 7Aug 2025: 12Sep 2025: 9Oct 2025: 25Nov 2025: 13Dec 2025: 82026Jan 2026: 3Feb 2026: 12Mar 2026: 13Apr 2026: 5May 2026: 5Jun 2026: 12

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

01362722008: 220082009: 42013: 220132014: 32015: 1620152016: 142017: 13220172018: 592019: 27220192020: 382021: 1220212022: 452023: 4820232024: 302025: 13520252026: 50

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of M-M-R Ii reports recording the termall reports in the database

  1. No adverse eventno adverse event was reported69.7%601
  2. Product storage errorthe product was stored wrongly24.8%214
  3. Expired product administeredthe product was used past its expiry date16.7%144
  4. Incorrect route of product administrationthe product was given by the wrong route4.9%42
  5. Inappropriate schedule of product administrationthe product was taken at the wrong times3.9%34
  6. Pyrexiafever3.4%29
  7. Incorrect product storagethe product was stored wrongly2.9%25
  8. Rashskin rash2.7%23
  9. Product preparation issuea problem preparing the product2.6%22
  10. Inappropriate schedule of drug administrationthe medicine was taken at the wrong times2.1%18
  11. Measles antibody negative2.1%18
  12. Accidental overdosean accidental overdose1.9%16
  13. Wrong drug administeredthe wrong medicine was given1.9%16
  14. Exposure during pregnancythe medicine was taken during pregnancy1.6%14
  15. Mumps antibody test negative1.5%13
  16. Rubella antibody negative1.5%13
  17. Antibody test negative1.4%12
  18. Incorrect dose administeredthe wrong dose was given1.4%12
  19. Anaphylactic reactiona severe, sudden allergic reaction1.3%11
  20. Incorrect route of drug administrationthe medicine was given by the wrong route1.3%11
  21. Overdosea dose above the recommended amount1.2%10
  22. Coughcough1%9

Top 30 of 124 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the share of all reports in the database; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Death0.7%6
Life-threatening0.8%7
Hospitalisation (initial or prolonged)2.9%25
Disability0.5%4
Congenital anomaly0%0
Other serious9.3%80
Not serious89.3%770

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Patient age

Under 215.8%136
2 to 118.6%74
12 to 171.9%16
18 to 449.2%79
45 to 645.7%49
65 to 741%9
75 and over0%0
Age not given57.9%499

Patient sex

Female24%207
Male15.9%137
Not given60.1%518

Who reported

Physician13.3%115
Pharmacist12.4%107
Other health professional62.1%535
Lawyer0.1%1
Consumer or non-health professional11.9%103
Not given0.1%1

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 95.6% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Prophylaxis77589.9%
Immunisation111.3%

The indication field is filled in by the reporter and is often blank; shares are of all 862 reports.

In context

MeasureM-M-R IiAll reports
Reports as suspect product86220,646,523
Share of that pool—0%
Reports, latest 12 months1241,332,454
Marked serious10.7%57.4%
Death recorded among outcomes, per 1,000 reports791
Hospitalisation recorded, per 1,000 reports29213
Consumer-filed share11.9%45.8%
Top term, share of reportsNo adverse event 69.7%0.8%

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Questions about M-M-R Ii reports

How many adverse event reports has FDA received for M-M-R Ii?

862 reports list M-M-R Ii as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 124 of them arrived in the latest 12 months. Another 77 list it only as a concomitant medication.

What reactions are recorded in M-M-R Ii reports?

no adverse event (69.7%), product storage error (24.8%), expired product administered (16.7%), incorrect route of product administration (4.9%) and product preparation error (4.4%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that M-M-R Ii was responsible.

How serious are the reports?

10.7% are marked serious by the reporter. Among the outcomes recorded, 0.7% of reports include death and 2.9% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.

Who files these reports?

other health professional (62.1%), physician (13.3%) and pharmacist (12.4%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for M-M-R Ii rising?

124 reports in the 12 months to June 2026, up 68% from 74 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.

Do these reports show that M-M-R Ii was responsible for these reactions?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.

Is this a list of the side effects of M-M-R Ii?

No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.

How do I report an adverse event?

Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists M-M-R Ii as a suspect or interacting product; reports listing it only as a concomitant medication (77) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.