What are the possible side effects of the Measles, Mumps, and Rubella (MMR) vaccine?

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Last updated: April 21, 2025View editorial policy

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From the Guidelines

The MMR vaccine is associated with a range of possible side effects, including mild reactions such as soreness or redness at the injection site, fever, mild rash, and temporary swelling of glands in the cheeks or neck, as well as more moderate side effects like joint pain or stiffness, temporary low platelet count, and seizures associated with fever, as reported in the study by 1. Some of the common adverse reactions to the rubella component of the MMR vaccine include transient rashes, which usually appear 7–10 days after vaccination in approximately 5% of vaccinated persons, or transient lymphadenopathy, fever, sore throat, and headache, as noted in the study by 1. In rare circumstances, MMR vaccination of adults has been associated with adverse events such as anaphylaxis, thrombocytopenia, and acute arthritis from the rubella component, with arthralgia developing among approximately 25% of rubella-susceptible postpubertal females after MMR vaccination, and approximately 10% having acute arthritis-like signs and symptoms from the rubella component of the vaccine, as reported in the study by 1. The study by 1 also found that MMR vaccine is associated with an increased risk for febrile seizures during the first 2 weeks after vaccination, particularly in children aged 12–23 months. However, it's essential to note that the benefits of the MMR vaccine in preventing potentially serious diseases significantly outweigh the risks of side effects, and most side effects are temporary and resolve within a few days, as stated in the study by 1. If you experience a high fever, unusual behavior, or severe allergic reaction after vaccination, seek medical attention immediately. Key points to consider include:

  • Mild side effects such as soreness or redness at the injection site, fever, mild rash, and temporary swelling of glands in the cheeks or neck
  • Moderate side effects like joint pain or stiffness, temporary low platelet count, and seizures associated with fever
  • Rare but severe side effects such as anaphylaxis, thrombocytopenia, and acute arthritis from the rubella component
  • Increased risk for febrile seizures during the first 2 weeks after vaccination, particularly in children aged 12–23 months
  • Benefits of the MMR vaccine in preventing potentially serious diseases outweigh the risks of side effects.

From the Research

Possible Side Effects of the MMR Vaccine

The MMR vaccine, like any other vaccine, can cause side effects in some individuals. According to a study published in 2001 2, some possible side effects of the MMR vaccine include:

  • Anaphylaxis
  • Urticaria with or without angioedema
  • Asthmatic symptoms
  • Henoch-Schönlein purpura These side effects can be caused by an allergic reaction to certain components of the vaccine, such as:
  • Gelatin
  • Egg
  • Chicken
  • Feathers
  • Cow's milk It is worth noting that severe allergic adverse events attributable to MMR vaccination are extremely rare, but all serious allergic reactions should be further assessed to detect the likely causative vaccine component, including gelatin 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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