ProQuad is a vaccine against measles, mumps, rubella, and varicella (chickenpox). ProQuad is a suspension given by subcutaneous injection (injection under the skin). The active substances are attenuated (weakened) viruses for the diseases.
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
ProQuad is given to children from 12 months of age to help protect them from the four diseases: measles, mumps, rubella, and varicella (chickenpox).
The medicine can only be obtained with a prescription.
ProQuad is provided as two separate components: a powder that must be kept frozen, and a solvent, in a vial or pre-filled syringe, that is kept in a refrigerator or at room temperature. Immediately before administration, the doctor or nurse will need to make up the suspension for injection by dissolving the frozen powder with the solvent. In order to protect against varicella (chickenpox), two doses of the weakened varicella virus are needed; this can be done either by giving two doses of ProQuad, or by giving a single dose of ProQuad followed by a dose of another vaccine that only protects against varicella. The second dose in both cases is given between one and three months after the first one.
ProQuad is a vaccine. Vaccines work by ?teaching? the immune system (the body?s natural defences) how to defend itself against a disease. ProQuad contains weakened forms of the viruses that cause measles, mumps, rubella, and chickenpox. When a person is given the vaccine, the immune system recognises the weakened viruses as ?foreign? and makes antibodies against them. In the future, the immune system will be able to produce antibodies quicker when it is again exposed to the viruses. The antibodies will help to protect against diseases caused by these viruses.
ProQuad contains well known weakened viruses, which are already used in other vaccines. When ProQuad was studied in humans, it was compared to its ?component vaccines?, a triple vaccine against mumps, measles and rubella, and a vaccine against varicella. The vaccine was studied in 5,446 healthy children (aged 12-23 months) who received one dose of ProQuad. The studies measured the
?immunogenicity? of the vaccine (its ability to make the immune system respond to the viruses). A study also looked at the responses one year after vaccination in 2,108 children.
The response rates (measuring how the immune system had responded to the viruses) were: 97.4% for measles, 95.8% to 98.8% for mumps, 98.5% for rubella and 91.2% for varicella. After the second dose, the rates were 99.4% for measles, 99.9% for mumps, 98.3% for rubella, and 99.4% for varicella.
The most common side-effect in the studies was fever (more than 1 child in 10). For the full list of all side effects reported with ProQuad, see the Package Leaflet.
Children should not be vaccinated with ProQuad if they have an allergy to any varicella vaccine or measles, mumps, or rubella vaccine, to any of the excipients, or to neomycin, or if they have any disease that affects their immune system. For the full list of restrictions, see the Package Leaflet.
The Committee for Medicinal Products for Human Use (CHMP) decided that ProQuad?s benefits are greater than its risks in the simultaneous vaccination against measles, mumps, rubella and varicella of individuals from 12 months of age. They recommended that ProQuad be given a marketing authorisation. They also recommended that a second dose of vaccination against varicella (chickenpox) should be given to complete protection against the disease.