Data from one of the largest infant vaccine trials, published in the New England Journal of Medicine (NEJM), confirms Rotarix (RIX4414) as effective against rotavirus disease (rotavirus gastroenteritis) in the first year of life.

Rotarix is the first vaccine available in several markets across the world to control the spread of this highly infectious disease, claims a GSK release.

Results from a double-blind, placebo-controlled trial demonstrated that two doses of Rotarix given two months apart at two and four months of age, protected 85% of infants from severe rotavirus and reached 100% efficacy against more severe rotavirus episodes. This protection was proven against the most common circulating strains (G1 and non-G1 rotavirus strains). In addition, high efficacy was shown against the globally emerging G9 strain1. Of further importance is that Rotarix demonstrated also a protective trend of heterotypic protection against the (non P8) G2P4 strain.

The safety analysis revealed less serious adverse events in the children receiving Rotarix compared to children in the placebo arm. This finding was attributable to the lower number of gastrointestinal disease related serious adverse events in those receiving Rotarix. In addition, the safety analysis looked for, but did not find, any evidence of an increased attributable risk for intussusception, a complication which was observed with a previous marketed vaccine. The most common adverse events reported with similar frequency in both study arms were irritability and loss of appetite, fever, fatigue, diarrhoea, vomiting, flatulence, abdominal pain and regurgitation of food.

Lead investigator Dr Guillermo M. Ruiz-Palacios, Instituto Nacional de Ciencas Medicas Nutricion, Mexico stated, "Rotavirus is highly contagious and infects virtually every child worldwide by the age of three years. It is the cause of two thirds of all hospitalisations due to gastroenteritits and is associated with a high mortality due to diarrhoea in developing countries. Rotarix has been shown to be highly effective in combating this disease. It should be considered for inclusion in the routine vaccination schedules in healthcare systems around the world."

According to the release, a total of 63,225 infants from 12 countries were enrolled in the study. Infants were randomly assigned to receive two oral doses of either Rotarix or placebo. After the administration of the first dose, the entire study population was followed for two to four months for the assessment of intussusception and serious adverse events. In addition a subgroup of 20,169 was followed up to one year of age for the assessment of efficacy.

Beatrice De Vos, director worldwide medical affairs, GSK Biologicals, said, "Rotavirus is highly contagious regardless of sanitary conditions. Rotavirus can be detected in about one-third of all children hospitalised for diarrhoea worldwide8 and mortality remains highest in the developing world. The now published data give confidence that vaccination at an early age has the potential to provide protection prior to the peak incidence of rotavirus (at 6-24 months of age) and therefore may preclude unnecessary illness, hospitalisation and death."

Rotarix has been developed by GlaxoSmithKline Biologicals since 1997. It is the first attenuated human rotavirus oral vaccine conferring protection against severe rotavirus diarrhoea with data that suggest efficacy against emergent strains. The vaccine is highly immunogenic and can be co-administered with all major infant vaccinations including oral polio vaccine.

Rotavirus is the leading recognised cause of diarrhoea-related illness and death among infants and young children. Every year, rotavirus is associated with an estimated number of 25 million clinic visits, two million hospitalisations and more than 600,000 deaths worldwide among children younger than five years of age.