Vaccine Info

Priorix Vaccine

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Last reviewed
August 22, 2023
Fact checked by
Robert Carlson, MD

Priorix MMR Vaccine 2023

GlaxoSmithKline (GSK) Priorix measles, mumps, and rubella (MMR) vaccine is a lyophilized mixed preparation of the attenuated Schwarz measles, RIT 4385 mumps derived from Jeryl Lynn strain, and Wistar RA 27/3 rubella strains of viruses. The measles and mumps components of the vaccine are produced in chick embryo cell culture and may contain traces of egg protein.

In June 2022, the U.S. Food and Drug Administration (FDA) approved Priorix (STN:125748) to prevent MMR in individuals 12 months of age and older. Globally, Priorix is recommended for use in individuals aged ≥9 months, according to a 1- or 2-dose schedule, depending on the country. PRIORIX is administered as an approximately 0.5-mL dose by subcutaneous injection. The first dose is administered at 12 to 15 months of age, and the second dose is administered at 4 to 6 years of age. Priorix has demonstrated noninferiority of the immune response compared to the M-M-R II® vaccine. Immune response to any of the antigens in PRIORIX or the coadministered vaccines was similar to the immune responses obtained when M-M-R II was coadministered with the same routine U.S. pediatric vaccines.

On June 23, 2022, Elisabeth Krow-Lucal, Ph.D. MPH Measles, Mumps, Rubella Vaccines Work Group, U.S. Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP), presented: Priorix for Prevention of MMR. Then on November 18, 2022, the CDC's MMWR: PRIORIX Recommendations of the ACIP - United States, 2022, confirmed PRIORIX and the M-M-R II vaccine are considered fully interchangeable, including for all off-label recommended uses. On February 9, 2023, the American Academy of Pediatrics supported the CDC's recommendation.

Priorix contains 9 mg of sorbitol, 6.5 nanograms of para-aminobenzoic acid per dose, and 334 micrograms of phenylalanine per dose. In addition, this vaccine has a trace amount of neomycin. Codes: CVX Code: 03, MVX Code: SKB, CPT Code: 90707, ICD-10-CM Code: Z23.

London-based GlaxoSmithKline plc (GSK) is a global healthcare company with a special purpose: to help people do more, feel better, and live longer. For further information, please GSK.

Priorix Availability 2023

Priorix was first registered in Germany in 1997 and is currently licensed in over 100 countries, including Canada, Europe, the U.K., and New Zealand. The U.S. FDA approved Priorix (STN:125748) for certain people on June 3, 2022. Priorix TETRA in Canada. As of January 2023, more than 800 million Priorix doses have been distributed.

Priorix Indication

Priorix is indicated to protect against MMR. It works by helping the body make antibodies that protect your child against these diseases. However, there are limited data on the use of PRIORIX in immunocompromised subjects; therefore, vaccination should be considered with caution, and only when, in the physician's opinion, the benefits outweigh the risks (e.g., asymptomatic HIV subjects).

Priorix Contraindications

Contraindications for Priorix are severe allergic reaction (e.g., anaphylaxis) to any component of Priorix or after a previous dose of any measles, mumps, and rubella-containing vaccine; severe immunodeficiency; and pregnancy or planning to become pregnant within the next month.

Priorix Women

Pregnant women must not be vaccinated with PRIORIX, says GSK. However, fetal damage has not been documented when MMR vaccines have been given to pregnant women. Therefore, inadvertent vaccination of unknowingly pregnant women with MMR-containing vaccines should not be a reason for the termination of pregnancy. Nevertheless, women of childbearing potential should be advised to avoid pregnancy for one month following vaccination. Furthermore, there are no human data regarding use in breastfeeding women. Nursing mothers may be vaccinated where the benefit outweighs the risk in the health professional's judgment.

Priorix Dosage

Priorix is administered as a subcutaneous or Intramuscular injection in the deltoid region or the anterolateral area of the thigh. A single 0.5 mL dose of the reconstituted vaccine is recommended. A second dose of MMR is recommended at least one month after the first dose for better measles protection. There is no difference between the first and second vaccine doses concerning the frequency category for the adverse reactions, except for pain at the injection site, which was "Common" after the first vaccine dose and "Very common" after the second vaccine dose.

Priorix Administration

Reconstitute the Lyophilized Antigen Component, Live only with the accompanying Sterile Water Diluent Component to form PRIORIX. The reconstituted vaccine should be a clear peach to fuchsia pink-colored suspension. Parenteral drug products should be inspected visually for particulate matter and discoloration before administration, whenever solution and container permit. If either of these conditions exists, do not administer the vaccine. Instead, administer PRIORIX immediately after reconstitution. If not used immediately, store refrigerated between 36° and 46° F (2° and 8°C) and administer within 8 hours. Discard reconstituted vaccine if not used within 8 hours.

Priorix Side Effects

Side effect information is available in the public domain via the Oxford Vaccine Knowledge Project. There is a risk of febrile seizure following immunization with Priorix, and thrombocytopenia and thrombocytopenic purpura have been reported following vaccination with Priorix. A summary of studies involving MMR studies can be found on their website:

Priorix-TETRA Vaccine

PRIORIX-TETRA is a sterile lyophilized mixed preparation containing the attenuated Schwarz measles virus strain, the RIT 4385 strain of mumps virus (derived from the Jeryl Lynn strain), the Wistar RA 27/3 rubella virus strain, and the OKA strain of the varicella-zoster virus. Each virus strain is separately produced in either chick embryo cells (mumps and measles) or MRC5 human diploid cells (rubella and varicella).

Although PRIORIX-TETRA contains live viruses, they are too weak to cause severe disease in healthy people. However, some spots, blisters, and fever may occasionally appear in the first two weeks after vaccination.

Priorix News 2023

February 10, 2023 - The AAFP and several other organizations co-released the 2023 adult and childhood/adolescent immunization schedules.

November 23, 2022 - The U.S. CDC and the WHO announced nearly 40 million children are susceptible to the growing measles threat.

November 18, 2022 - U.S. CDC ACIP Recommendation: Priorix is recommended according to the existing MMR recommended schedules and off-label uses as an option to prevent measles, mumps, and rubella.

June 6, 2022 - GSK announced the U.S. FDA-approved the Priorix vaccine for most people over the age of one year.

February 23, 2022 - Remon Abu-Elyazeed, MD, Ph.D., presented 'Overview of GSK's MMR Vaccine' during the CDC's ACIP vaccine committee meeting.

August 2, 2021 - GSK submitted a Biologics License Application to the U.S. FDA for PRIORIX and is seeking approval for active immunization against infection by MMR.

March 24, 2021 - Vaccine manufacturers across the globe have been focusing on partnering with organizations such as WHO, UNICEF, and GAVI Alliance to improve their vaccination programs to reach the maximum population to offer vaccines. Despite several governmental initiatives, measles is a leading cause of death among young children. 

April 30, 2020 - Study: Immunogenicity and Safety of an MMR Vaccine Administered as the First Dose to Children Aged 12 to 15 Months: A Phase III, Randomized, Noninferiority, Lot-to-Lot Consistency Study. Conclusions: If licensed, the MMR-RIT could provide a valid option for preventing measles, mumps, and rubella in children in the United States and reduce the potential risks of a vaccine shortage.

January 12, 2020 - A study published in the Pediatric Infectious Disease Society concluded, 'if licensed, the Priorix / MMR-RIT vaccine could provide a valid option for preventing MMR in children, 12-to 15 months old in the U.S.

March 22, 2019 - A phase 3 study published in the Pediatric Infectious Diseases Society Journal found that GlaxoSmithKline's MMR vaccine was safe and effective in healthy children.

Priorix Vaccine Clinical Trials

GSK continues to test the safety and efficacy of Priorix in clinical trials.