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Priorix

Priorix - Powder and solvent for solution for injection in a pre-filled syringe

Manufacturer
GlaxoSmithKline UK
Label last updated
02 Jan 2026
Source
Official SmPC ↗

MMR vaccine - measles, mumps and rubella - for children from 9 months. Three live weakened viruses, two of them grown on chick embryo cells and one on human foetal lung cells.

61 findings, each with the section of the label it comes from.

Ingredients and materials

  • Live attenuated measles virus, Schwarz strain, not less than 10^3.0 CCID50 per 0.5 ml doses.2
  • Live attenuated mumps virus, RIT 4385 strain, derived from the Jeryl Lynn strain, not less than 10^3.7 CCID50s.2
  • Live attenuated rubella virus, Wistar RA 27/3 strain, not less than 10^3.0 CCID50s.2
  • Measles and mumps are produced in chick embryo cells; rubella is produced in human diploid MRC-5 cells - a cell line originally derived from human foetal lung tissues.2
  • Contains a trace amount of neomycin; hypersensitivity to neomycin is a contraindication, though a history of contact dermatitis to neomycin is nots.2, 4.3
  • Powder excipients: amino acids containing phenylalanine, lactose anhydrous, mannitol (E421), sorbitol (E420), Medium 199 containing phenylalanine, para-aminobenzoic acid, sodium and potassiums.6.1
  • Solvent: water for injectionss.6.1
  • Contains 9 mg sorbitol, 6.5 nanograms of para-aminobenzoic acid and 334 micrograms of phenylalanine, the last of which may be harmful in phenylketonuria (PKU)s.2, 4.4
  • Para-aminobenzoic acid may cause allergic reactions, possibly delayed, and exceptionally bronchospasms.4.4
  • Declared essentially sodium-free and potassium-free, less than 1 mmol of each per doses.4.4

Manufacture, storage and handling

  • Shelf life 2 yearss.6.3
  • Store and transport refrigerated at 2C to 8C, do not freeze, store in the original package to protect from lights.6.4
  • The vaccine should be injected promptly after reconstitution; if that is not possible it must be kept at 2C to 8C and used within 8 hourss.6.3
  • Reconstituted by adding the whole syringe of solvent to the powder vial and shaking until completely dissolved; a new needle must be used to administers.6.6
  • The reconstituted vaccine may vary in colour from clear peach to fuchsia pink because of minor pH variation, without deterioration of potencys.6.6
  • If the Luer Lock Adaptor comes off during syringe assembly, a new vaccine dose with a new syringe and vial should be useds.6.6
  • Subcutaneous injection, or intramuscular in the deltoid or anterolateral thigh; preferably subcutaneous in people with thrombocytopenia or a coagulation disorders.4.2
  • Must under no circumstances be administered intravascularly - accidental intravascular administration may give rise to severe reactions or even shocks.4.4, 4.8
  • Alcohol and other disinfecting agents must be allowed to evaporate from the skin before injection because they can inactivate the attenuated virusess.4.4
  • Must not be mixed with other medicinal products; no compatibility studies exists.6.2

Safety findings

  • Licensed from 9 months of age; the safety and efficacy of PRIORIX in infants under 9 months have not been establisheds.4.1, 4.2
  • Infants in their first year of life may not respond sufficiently to the components, probably because of interference from maternal antibodies, so if a first-year dose is needed for an outbreak or travel, a second dose should be given in the second year of life, preferably within 3 months, and never less than 4 weeks aparts.4.2, 4.4
  • Contraindicated in pregnancy, and pregnancy should be avoided for 1 month after vaccinations.4.3, 4.6
  • Contraindicated in current immunosuppressive therapy including high doses of corticosteroids, but not in people receiving topical or low-dose parenteral corticosteroidss.4.3
  • Contraindicated in severe humoral or cellular immunodeficiency, whether primary or acquired, including severe combined immunodeficiency, agammaglobulinemia, AIDS or symptomatic HIV infection, or an age-specific CD4+ T-lymphocyte percentage below 25 per cent under 12 months, below 20 per cent at 12 to 35 months, and below 15 per cent at 36 to 59 monthss.4.3
  • Contraindicated in hypersensitivity to the active substances, excipients or neomycins.4.3
  • Vaccination should be postponed during acute severe febrile illness; a minor infection such as a cold is not a reason to defers.4.3
  • Due caution is advised in people with a central nervous system disorder, susceptibility to febrile convulsions, or a family history of convulsions; those with a history of febrile convulsions should be closely followed ups.4.4
  • Individuals who have experienced anaphylaxis after eating egg should be vaccinated with extreme caution with adequate treatment for anaphylaxis on hand, because the measles and mumps components are produced in chick embryo cell culture and may contain traces of egg proteins.4.4
  • Immunocompromised patients without a contraindication may not respond as well as immunocompetent people and may still acquire measles, mumps or rubella on contact despite vaccination, so they should be monitored carefully for signs of these diseasess.4.4
  • Transmission of measles and mumps virus from vaccinees to susceptible contacts has never been documented, though pharyngeal excretion of rubella and measles virus is known to occur about 7 to 28 days after vaccination, peaking around day 11, with no evidence of transmission to susceptible contactss.4.4
  • Transmission of the rubella vaccine virus to infants via breast milk, and transplacental transmission, have been documented without any evidence of clinical diseases.4.4
  • Breastfeeding: there is limited experience. Breastfeeding women vaccinated with live attenuated rubella vaccines may secrete the virus in breast milk and transmit it to breastfed infants without evidence of symptomatic disease. Risks and benefits should be evaluated only if the child is confirmed or suspected to be immunodeficients.4.6
  • Cases of worsening and of recurrence of thrombocytopenia have been reported after live measles, mumps and rubella vaccines in people who had thrombocytopenia after the first dose; this is rare and generally self-limited, but the risk-benefit should be evaluated carefully and these patients vaccinated with caution, preferably subcutaneouslys.4.4
  • As with any vaccine, a protective immune response may not be elicited in all vaccineess.4.4
  • Very common reactions: redness at the injection site, and fever of 38C or above rectally or 37.5C or above by mouth or under the arms.4.8
  • Common reactions: pain and swelling at the injection site, fever above 39.5C rectally or 39C otherwise, rash, upper respiratory tract infections.4.8
  • Listed as rare in clinical trials: allergic reactions, and febrile convulsionss.4.8
  • Post-marketing reports include meningitis, measles-like syndrome, mumps-like syndrome including orchitis, epididymitis and parotitis, thrombocytopenia and thrombocytopenic purpura, anaphylactic reactions, encephalitis, cerebellitis and cerebellitis-like symptoms including transient gait disturbance and ataxia, Guillain-Barre syndrome, transverse myelitis, peripheral neuritis, vasculitis, erythema multiforme, arthralgia and arthritiss.4.8
  • The label puts the encephalitis risk in context: reported with a frequency below 1 per 10 million doses, which is 'far below' the risk of encephalitis from the natural diseases - measles 1 in 1,000 to 2,000 cases, mumps 2 to 4 in 1,000, rubella about 1 in 6,000s.4.8
  • Pregnancy: in a review of more than 3,500 susceptible women unknowingly in early pregnancy when vaccinated with a rubella-containing vaccine, no cases of congenital rubella syndrome were reported, but subsequent post-marketing surveillance identified congenital rubella syndrome associated with the Wistar RA 27/3 rubella vaccine strain after inadvertent vaccination in pregnancys.4.6
  • Foetal damage has not been documented when measles or mumps vaccines have been given to pregnant womens.4.6
  • Fertility: the vaccine has not been evaluated in fertility studiess.4.6
  • If not given at the same time, an interval of at least one month is recommended between PRIORIX and other live attenuated vacciness.4.5
  • Tuberculin testing should be done before or at the same time as vaccination, because MMR vaccines may cause a temporary depression of tuberculin skin sensitivity lasting up to 6 weeks, giving false negative resultss.4.5
  • In people who have received human gammaglobulins or a blood transfusion, vaccination should be delayed for three months or longer, up to 11 months, depending on the dose of globulins, because of the likelihood of vaccine failure from passively acquired antibodiess.4.5
  • Because of an increased risk of fever, tenderness at the injection site, change in eating habits and irritability when the MenB vaccine is given with a combined MMR and varicella vaccine, separate vaccination can be considered where possibles.4.5
  • Overdose, up to twice the recommended dose, has been reported in post-marketing surveillance with no adverse events associated with its.4.9

Evidence and claims

  • A single dose induced antibodies against measles in 98.1 per cent, mumps in 94.4 per cent and rubella in 100 per cent of previously seronegative vaccinees; two years after primary vaccination the rates were 93.4, 94.4 and 100 per cents.5.1
  • 'Although there are no data available concerning the protective efficacy of PRIORIX, immunogenicity is accepted as an indication of protective efficacy. However, some field studies report that the effectiveness against mumps may be lower than the observed seroconversion rates to mumps's.5.1
  • In 300 children aged 9 to 10 months, seroconversion rates after the first dose were 92.6 per cent for measles, 91.5 per cent for mumps and 100 per cent for rubella, rising after a second dose to 100, 99.2 and 100 per cent - the basis for the recommendation to give a second dose within three months in this age groups.5.1
  • The safety and immunogenicity of PRIORIX in adolescents and adults has not been specifically studied in clinical trialss.5.1
  • Only a limited number of subjects received PRIORIX intramuscularly in clinical trials, and seroconversion rates were comparable to subcutaneous administrations.5.1
  • The safety profile is based on approximately 12,000 subjects given PRIORIX in clinical trials, with signs and symptoms actively monitored for 42 dayss.4.8
  • The frequency category for adverse reactions was similar for the first and second doses, except pain at the injection site which was common after the first dose and very common after the seconds.4.8
  • Preclinical data reveal no special hazard for humans based on general safety studiess.5.3

Document and licensing

  • Marketing authorisation holder: SmithKline Beecham Limited, London, trading as GlaxoSmithKline UKs.7
  • First authorised 4 December 1997, last renewal 3 December 2002s.9
  • Text last revised 12 December 2025s.10
  • The label states that no data on protective efficacy exist and that antibody levels are accepted as the indication of it, and gives the encephalitis risk alongside the much higher risk from the natural diseasess.5.1, 4.8
  • Suspected reactions are reported through the MHRA Yellow Card schemes.4.8

Every line above is a summary of a statement in the manufacturer's own label, with the section number it comes from. Nothing has been added from any other source. The full list of flagged sentences is below, as it came out of the document.

Listed ingredients

Section 2 - qualitative and quantitative composition source ↗

After reconstitution, 1 dose (0.5 ml) contains: 
 Live attenuated measles virus^1 (Schwarz strain)
 not less than 10^3.0 CCID50^3
 Live attenuated mumps virus^1 (RIT 4385 strain, derived from Jeryl Lynn strain)
 not less than 10^3.7 CCID50^3
 Live attenuated rubella virus^2 (Wistar RA 27/3 strain)
 not less than 10^3.0 CCID50^3
 ^1 produced in chick embryo cells
 ^2 produced in human diploid (MRC-5) cells
 ^3 Cell Culture Infective Dose 50 %
 This vaccine contains a trace amount of neomycin. See section 4.3.
 Excipients with known effect 
 The vaccine contains 9 mg of sorbitol.
 The vaccine contains 6.5 nanograms of para-aminobenzoic acid per dose and 334 micrograms of phenylalanine per dose (see section 4.4).
 For the full list of excipients, see section 6.1.

What these are, in plain English

  • attenuated - Weakened on purpose so the organism cannot cause the disease in a healthy person.
  • neomycin - An antibiotic used during manufacture to stop bacteria growing. Traces may remain, which is why a neomycin allergy is a contraindication.
  • sorbitol - A sugar alcohol used as a stabiliser and to give the liquid bulk. Also found in sugar-free food.
  • para-aminobenzoic acid - A vitamin-like nutrient, sometimes called PABA, used to grow the cells.
  • phenylalanine - An amino acid. People with the inherited condition phenylketonuria (PKU) have to limit it, which is why it is declared.

Other ingredients (excipients)

Section 6.1 source ↗

  • Powder:
  • Amino acids (containing phenylalanine)The building blocks of protein, present here as nutrients for the cells grown during manufacture.
  • Lactose (anhydrous)Milk sugar, used as a stabiliser and bulking agent.
  • Mannitol (E 421)A sugar alcohol used as a stabiliser and bulking agent, so the dried powder forms a proper cake.
  • Sorbitol (E 420)A sugar alcohol used as a stabiliser and to give the liquid bulk. Also found in sugar-free food.
  • Medium 199 (containing phenylalanine, para-aminobenzoic acid, sodium and potassium)A standard laboratory nutrient mixture (salts, vitamins, amino acids, sugars) that cells are grown in. Its residues are diluted out almost entirely.
  • Solvent:
  • Water for injectionsPurified water to the standard used for injected medicines. It is the liquid the other ingredients are dissolved in.
Audit trail: every flagged sentence in the document (37)

These are the sentences the mechanical filter pulled out, in the document's own words, grouped by section. They are what the briefing above was built from, kept here so you can check nothing was left out. Some are fragments and some are technical, which is why the briefing exists.

4.2 Posology and method of administration

  1. The safety and efficacy of PRIORIX in infants under 9 months of age has not been established.

    Section 4.2 Posology and method of administration source ↗

    In plain English

    • not been established - There is not yet enough evidence to state a conclusion.
    • efficacy - How well it works in the controlled conditions of a trial.

    Efficacy, effectiveness and endpointsNo data / not studied matched: efficacy, not been established

4.3 Contraindications

  1. Hypersensitivity to the active substances or to any of the excipients listed in section 6.1 or neomycin.

    Section 4.3 Contraindications source ↗

    In plain English

    • hypersensitivity - An allergic-type reaction, from a mild rash up to a severe reaction.

    Trace residues and process chemicals matched: neomycin

  2. A history of contact dermatitis to neomycin is not a contraindication.

    Section 4.3 Contraindications source ↗

    Trace residues and process chemicals matched: neomycin

  3. For hypersensitivity reactions to egg proteins, see section 4.4.

    Section 4.3 Contraindications source ↗

    In plain English

    • hypersensitivity - An allergic-type reaction, from a mild rash up to a severe reaction.

    Animal, human or cell-line derived material matched: egg

  4. Priorix is not contraindicated in individuals who are receiving topical or low-dose parenteral corticosteroids (e.g. for asthma prophylaxis or replacement therapy).

    Section 4.3 Contraindications source ↗

    In plain English

    • contraindicated - A situation where the medicine should not be given at all.

    Not recommended, contraindicated or restricted matched: contraindicated

  5. Furthermore, pregnancy should be avoided for 1 month following vaccination (see Section 4.6).

    Section 4.3 Contraindications source ↗

    Not recommended, contraindicated or restricted matched: should be avoided

4.4 Special warnings and precautions for use

  1. Alcohol and other disinfecting agents must be allowed to evaporate from the skin before injection of the vaccine since they can inactivate the attenuated viruses in the vaccine.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • attenuated - Weakened on purpose so the virus or bacterium can no longer cause the disease in a healthy person.

    Genetic engineering, vectors and GMOs matched: attenuated

  2. The measles and mumps components of the vaccine are produced in chick embryo cell culture and may therefore contain traces of egg protein.

    Section 4.4 Special warnings and precautions for use source ↗

    Animal, human or cell-line derived material matched: egg

  3. Persons with a history of anaphylactic, anaphylactoid, or other immediate reactions (e.g. generalised urticaria, swelling of the mouth and throat, difficulty in breathing, hypotension, or shock) subsequent to egg ingestion may be at an enhanced risk of immediate-type hypersensitivity reactions after vaccination, although these types of reactions have been shown to be very rare.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • hypersensitivity - An allergic-type reaction, from a mild rash up to a severe reaction.
    • very rare - In the label's frequency scale, this means it happened in up to 1 in 10,000 people. Often these are reports sent in after a vaccine is in use rather than findings from a formal study.

    Animal, human or cell-line derived materialRare or very rare serious events matched: egg, very rare

  4. Individuals who have experienced anaphylaxis after egg ingestion should be vaccinated with extreme caution, with adequate treatment for anaphylaxis on hand should such a reaction occur.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • anaphylaxis - A severe, sudden allergic reaction that can make breathing difficult and needs urgent medical treatment.

    Animal, human or cell-line derived material matched: egg

  5. As with any vaccine, a protective immune response may not be elicited in all vaccinees.

    Section 4.4 Special warnings and precautions for use source ↗

    Efficacy, effectiveness and endpoints matched: immune response

  6. Cases of worsening of thrombocytopenia and cases of recurrence of thrombocytopenia in subjects who suffered thrombocytopenia after the first dose have been reported following vaccination with live measles, mumps and rubella vaccines.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • thrombocytopenia - A low platelet count, which makes bruising and bleeding easier.

    Genetic engineering, vectors and GMOs matched: live

  7. Immunocompromised patients who have no contraindication for this vaccination (see section 4.3) may not respond as well as immunocompetent subjects, therefore some of these patients may acquire measles, mumps or rubella in case of contact, despite appropriate vaccine administration.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • immunocompromised - Having a weakened immune system, from illness or from medicines such as chemotherapy.

    Immune system, shedding and transmission matched: immunocompromised

  8. Transmission of measles and mumps virus from vaccinees to susceptible contacts has never been documented.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • transmission - Passing something from one person to another.

    Immune system, shedding and transmission matched: transmission

  9. However there is no evidence of transmission of these excreted vaccine viruses to susceptible contacts.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • transmission - Passing something from one person to another.

    Immune system, shedding and transmission matched: transmission

  10. Transmission of the rubella vaccine virus to infants via breast milk as well as transplacental transmission has been documented without any evidence of clinical disease.

    Section 4.4 Special warnings and precautions for use source ↗

    In plain English

    • transmission - Passing something from one person to another.

    Immune system, shedding and transmission matched: transmission

4.5 Interaction with other medicinal products and other forms of interaction

  1. There are no data to support the use of PRIORIX with any other vaccines.

    Section 4.5 Interaction with other medicinal products and other forms of interaction source ↗

    In plain English

    • no data - The label is stating that no study has measured this. It is a statement about what was tested, not about what was found.

    No data / not studied matched: no data

  2. If not given at the same time, an interval of at least one month is recommended between administration of PRIORIX and other live attenuated vaccines.

    Section 4.5 Interaction with other medicinal products and other forms of interaction source ↗

    In plain English

    • live attenuated - A vaccine containing a weakened but still living organism. It can still replicate in the body and, with a nasal flu vaccine, be passed on.

    Genetic engineering, vectors and GMOs matched: attenuated

  3. In subjects who have received human gammaglobulins or a blood transfusion, vaccination should be delayed for three months or longer (up to 11 months) depending on the dose of human globulins administered because of the likelihood of vaccine failure due to passively acquired measles, mumps and rubella antibodies.

    Section 4.5 Interaction with other medicinal products and other forms of interaction source ↗

    Animal, human or cell-line derived material matched: blood

4.6 Fertility, pregnancy and lactation

  1. PRIORIX has not been evaluated in fertility studies.

    Section 4.6 Fertility, pregnancy and lactation source ↗

    In plain English

    • has not been evaluated - It has not been tested or measured in this group or situation.

    No data / not studied matched: has not been evaluated

  2. Foetal damage has not been documented when measles or mumps vaccines have been given to pregnant women.

    Section 4.6 Fertility, pregnancy and lactation source ↗

    Animal, human or cell-line derived material matched: foetal

  3. Pregnancy should be avoided for 1 month following vaccination.

    Section 4.6 Fertility, pregnancy and lactation source ↗

    Not recommended, contraindicated or restricted matched: should be avoided

  4. There is limited experience with PRIORIX during breast-feeding.

    Section 4.6 Fertility, pregnancy and lactation source ↗

    In plain English

    • limited experience - The product has been used only a small number of times in this group.

    Limited, insufficient or inconclusive matched: limited experience

  5. Studies have shown that breast-feeding postpartum women vaccinated with live attenuated rubella vaccines may secrete the virus in breast milk and transmit it to breast-fed infants without evidence of any symptomatic disease.

    Section 4.6 Fertility, pregnancy and lactation source ↗

    In plain English

    • live attenuated - A vaccine containing a weakened but still living organism. It can still replicate in the body and, with a nasal flu vaccine, be passed on.

    Genetic engineering, vectors and GMOsImmune system, shedding and transmission matched: attenuated, transmit

4.8 Undesirable effects

  1. Meningitis, measles-like syndrome, mumps-like syndrome (including orchitis, epididymitis and parotitis)

    Section 4.8 Undesirable effects source ↗

    In plain English

    • meningitis - Inflammation of the lining around the brain and spinal cord.

    Rare or very rare serious events matched: meningitis

  2. Encephalitis*, cerebellitis, cerebellitis like symptoms (including transient gait disturbance and transient ataxia), Guillain-Barré syndrome, transverse myelitis, peripheral neuritis

    Section 4.8 Undesirable effects source ↗

    In plain English

    • encephalitis - Inflammation of the brain.

    Rare or very rare serious events matched: guillain

5.1 Pharmacodynamic properties

  1. Immune response in children 12 months and older

    Section 5.1 Pharmacodynamic properties source ↗

    Efficacy, effectiveness and endpoints matched: immune response

  2. Two years after primary vaccination seroconversion rates were 93.4 % for measles, 94.4 % for mumps and 100 % for rubella.

    Section 5.1 Pharmacodynamic properties source ↗

    In plain English

    • seroconversion - A rise in antibodies after vaccination, measured in the blood.

    Efficacy, effectiveness and endpoints matched: seroconversion

  3. Although there are no data available concerning the protective efficacy of PRIORIX, immunogenicity is accepted as an indication of protective efficacy.

    Section 5.1 Pharmacodynamic properties source ↗

    In plain English

    • immunogenicity - How strongly the vaccine provokes an immune response. It is measured in the blood, not by how many people avoided the illness.
    • efficacy - How well it works in the controlled conditions of a trial.
    • no data - The label is stating that no study has measured this. It is a statement about what was tested, not about what was found.

    Efficacy, effectiveness and endpointsNo data / not studied matched: efficacy, no data

  4. However, some field studies report that the effectiveness against mumps may be lower than the observed seroconversion rates to mumps.

    Section 5.1 Pharmacodynamic properties source ↗

    In plain English

    • seroconversion - A rise in antibodies after vaccination, measured in the blood.
    • effectiveness - How well it works in ordinary use in the real world.

    Efficacy, effectiveness and endpoints matched: effectiveness

  5. Immune response in children aged 9 to 10 months

    Section 5.1 Pharmacodynamic properties source ↗

    Efficacy, effectiveness and endpoints matched: immune response

  6. Seroconversion rates for measles, mumps and rubella were 92.6 %, 91.5 % and 100 %, respectively.

    Section 5.1 Pharmacodynamic properties source ↗

    In plain English

    • seroconversion - A rise in antibodies after vaccination, measured in the blood.

    Efficacy, effectiveness and endpoints matched: seroconversion

  7. The seroconversion rates reported following the second dose given 3 months after the first dose were 100 % for measles, 99.2 % for mumps and 100 % for rubella.

    Section 5.1 Pharmacodynamic properties source ↗

    In plain English

    • seroconversion - A rise in antibodies after vaccination, measured in the blood.

    Efficacy, effectiveness and endpoints matched: seroconversion

  8. The seroconversion rates to the three components were comparable to those seen after subcutaneous administration.

    Section 5.1 Pharmacodynamic properties source ↗

    In plain English

    • seroconversion - A rise in antibodies after vaccination, measured in the blood.

    Efficacy, effectiveness and endpoints matched: seroconversion

6.3 Shelf life

  1. If this is not possible, it must be stored at 2° C-8° C and used within 8 hours of reconstitution.

    Section 6.3 Shelf life source ↗

    Limited, insufficient or inconclusive matched: not possible

6.6 Special precautions for disposal and other handling

  1. In the event of either being observed, do not use the solvent or the reconstituted vaccine.

    Section 6.6 Special precautions for disposal and other handling source ↗

    Not recommended, contraindicated or restricted matched: do not use

  2. Contacts with disinfectants should be avoided (see section 4.4).

    Section 6.6 Special precautions for disposal and other handling source ↗

    Not recommended, contraindicated or restricted matched: should be avoided

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