The Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) has published an updated recommendation to include the use of Priorix  (measles, mumps and rubella vaccine, live) as an additional option for active immunization for the prevention of measles, mumps and rubella in individuals 12 months of age and older.

Priorix is administered as a 2-dose series (each dose is approximately 0.5mL) via subcutaneous injection. The first dose is administered at 12 to 15 months of age; the second dose at 4 to 6 years of age. The vaccine may also be administered as a second dose to individuals who have received the first dose of another MMR-containing vaccine.

The recommendation was based on safety data from 4 randomized controlled clinical studies, 4 observational studies and 1 systematic review. In the randomized controlled trials, participants received at least 1 dose of either Priorix or a US-licensed MMR virus vaccine, live (M-M-R® II).

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Results showed that immune responses after Priorix administration were noninferior to those observed with M-M-R II. Additionally, no significant difference in the frequency of vaccine-related serious adverse events was reported in these studies.

Based on these findings, the CDC considers Priorix and M-M-R II to be fully interchangeable. Either vaccine may be administered when an MMR virus-containing vaccine is indicated.


  1. US Centers for Disease Control and Prevention. Measles, Mumps, Rubella Vaccine (PRIORIX): Recommendations of the Advisory Committee on Immunization Practices — United States, 2022.. Published online November 18, 2022. Morbidity and Mortality Weekly Report.
  2. Priorix. Package Insert. GlaxoSmithKline plc; 2022. Accessed November 18, 2022.

This article originally appeared on MPR