Priorix

Priorix
Type	Combination vaccine
Target	Measles, Mumps, Rubella
Tradename	Priorix
Manufacturer	GlaxoSmithKline
ATC prefix	J07
ATC suffix	BD52

Priorix. It is a live attenuated vaccine used for immunization against measles, mumps, and rubella, commonly known as MMR vaccine. Manufactured by the multinational pharmaceutical company GlaxoSmithKline, it is a key tool in global public health initiatives led by organizations like the World Health Organization for the prevention of these contagious viral diseases. The vaccine contains weakened strains of the respective viruses, stimulating an immune response without causing the actual illnesses.

Composition and formulation

The vaccine is formulated with live, attenuated strains of the Edmonston-Zagreb measles virus, the RIT 4385 mumps virus (derived from the Jeryl Lynn strain), and the Wistar RA 27/3 rubella virus. These viral components are propagated in cultures of either chick embryo fibroblasts or human diploid cell lines, such as MRC-5 cells. The final product is a lyophilized powder that is reconstituted with a supplied diluent, typically a sterile water for injection, prior to administration. Excipients include stabilizers like sorbitol and lactose, along with amino acids and buffers to maintain viability and potency.

Indications and usage

Priorix is indicated for active immunization of individuals 12 months of age and older against measles, mumps, and rubella. Its primary use is in routine childhood immunization programs, as recommended by bodies like the Centers for Disease Control and Prevention and the European Medicines Agency. It is also used in catch-up vaccination campaigns for older children, adolescents, and adults who lack evidence of immunity, particularly for susceptible women of childbearing age to prevent congenital rubella syndrome. The vaccine can be administered as part of outbreak control measures under the guidance of national health authorities like Public Health England.

Efficacy and clinical trials

Clinical trials and extensive post-marketing surveillance have demonstrated high efficacy for Priorix. Seroconversion rates, indicating successful immune response, typically exceed 95% for the measles component, 90% for the mumps component, and 99% for the rubella component after a single dose. Pivotal studies conducted by GlaxoSmithKline and reviewed by regulatory agencies such as the Food and Drug Administration have confirmed its immunogenicity and safety profile. The vaccine's performance is considered non-inferior to other available MMR vaccine products, contributing to the dramatic reduction in disease incidence in regions with high vaccination coverage, as documented in publications like the Morbidity and Mortality Weekly Report.

Administration and dosage

The standard regimen consists of two doses administered via subcutaneous injection, preferably in the upper arm's deltoid muscle or the anterolateral thigh. The first dose is recommended at 12 through 15 months of age, with a second dose given before school entry, typically between 4 and 6 years of age, as per schedules from the Advisory Committee on Immunization Practices. The minimum interval between doses is 28 days. For adolescents and adults without prior vaccination, two doses spaced at least 28 days apart are also recommended. Each dose is 0.5 mL of the reconstituted vaccine.

Safety and side effects

The vaccine is generally well-tolerated, with most adverse reactions being mild and transient. Common local reactions include pain, redness, and swelling at the injection site. Systemic reactions may include fever, rash, and parotid gland swelling, typically occurring 5 to 12 days post-vaccination. Extensive studies, including those published in journals like The Lancet and The New England Journal of Medicine, have found no causal link between the vaccine and conditions such as autism or inflammatory bowel disease. As with all live vaccines, it is contraindicated in individuals with severe immunodeficiency, such as those undergoing chemotherapy for leukemia or with advanced HIV infection, and in pregnancy.

Storage and handling

Priorix must be stored and transported under continuous cold chain conditions at temperatures between +2°C and +8°C to maintain stability. The lyophilized powder should be protected from light. Reconstitution must be performed using only the supplied diluent and aseptic technique; the vaccine should be used immediately after reconstitution, typically within 8 hours if stored at the recommended temperature. Unused vaccine or waste material should be disposed of in accordance with biohazard regulations from agencies like the Occupational Safety and Health Administration.

Category:Vaccines Category:GlaxoSmithKline