Adverse Events After Third Dose of Measles-Mumps-Rubella Vaccine

Investigators from the CDC and the Marshfield Clinic Research Institute, Marshfield, WI, conducted a prospective study to assess adverse events associated with a third dose of measles-mumps-rubella vaccine (MMR3). In 2017, the Advisory Committee on Immunization Practices recommended MMR3 for individuals at increased risk of mumps during an outbreak; MMR3 also may be administered for other reasons, such as lack of documentation of 2 prior doses.¹ Study participants were volunteers, 18–31 years old, who had 2 documented prior doses of MMR vaccine. On the day of vaccine administration, participants were asked to report the presence of the following symptoms on a daily basis during the 14 preceding days: fever, coryza, cough, conjunctivitis, vomiting, diarrhea, jaw swelling, lymphadenopathy, …