drugs

ProQuad - vaccine

Characteristics of the medicinal product

ProQuad is a vaccine against measles, mumps, rubella and chickenpox. ProQuad is a suspension that can be administered subcutaneously (ie by injection under the skin). The active ingredients are attenuated (weakened) viruses that cause individual diseases.

Therapeutic indications

ProQuad is given to children over 12 months to help protect them from the four diseases: measles, mumps, rubella and chickenpox. The drug can only be obtained on prescription.

Method of use

ProQuad is available as two components: a powder that must be kept frozen and a solvent contained in a bottle or in a pre-filled syringe, which is stored in the refrigerator or at room temperature. Immediately before administration, the doctor or nurse will have to prepare the suspension for injection by dissolving the frozen powder with the solvent.

To protect from chickenpox two doses of the weakened varicella virus are needed; for this purpose two doses of ProQuad or a single dose can be administered followed by a dose of another vaccine that only protects from chickenpox. The second dose in both cases is administered 1-3 months after the first dose.

Mechanisms of action

ProQuad is a vaccine. Vaccines act by "teaching" the immune system (the body's natural defenses) to defend itself against a disease. ProQuad contains attenuated forms of the viruses that cause measles, mumps, rubella and chickenpox. When the vaccine is given, the immune system recognizes attenuated viruses as "foreign" and produces antibodies against them. In the future, the immune system will be able to produce antibodies more quickly when it is exposed to viruses again. Antibodies will help protect the body from diseases caused by these viruses.

Studies carried out

ProQuad contains well-known and already used attenuated viruses in other vaccines. When ProQuad was studied in humans, it was compared to the "component vaccines", ie with a triple measles vaccine, mumps and rubella and a varicella vaccine. The vaccine was studied in 5446 healthy children (12-23 months) who received a dose of ProQuad. The studies performed measured the "immunogenicity" of the vaccine (ie its ability to make the immune system respond to viruses). One study also examined the responses one year after vaccination in 2 108 children.

Benefits found following the studies

Response rates (which measure how the immune system responded to viruses) were 97.4% for measles, 95.8% for mumps, 98.5% for rubella and 91, 2% for chickenpox. After the second dose, response rates were 99.4% for measles, 99.9% for mumps, 98.3% for rubella and 99.4% for varicella, respectively.

Associated risks

The most common side effect observed in the studies performed was fever (more than one in 10 children). For a complete list of all side effects reported with ProQuad, see the product information leaflet. We must avoid vaccinating children with Proquad if they experience an allergy to any type of vaccine against chickenpox, measles, mumps and rubella, to any excipient they contain, to neomycin, or if they are suffering from immune disorders.

For a complete list of all restrictions, refer to the product information leaflet.

Grounds for approval

The Committee for Medicinal Products for Human Use (CHMP) has decided that the benefits of ProQuad outweigh the risks it entails in contemporary vaccination against measles, mumps, rubella and chickenpox in children over 12 months of age. The Committee recommended that ProQuad be given marketing authorization, advising that a second dose of varicella vaccine be given to complete protection from the disease.

Further information

On 6 April 2006, the European Commission issued a marketing authorization for ProQuad to Sanofi Pasteur MSD SNC valid throughout the European Union.

The full version of the EPAR for ProQuad is available by clicking here.

Last update: 04-2006