The US Food and Drug Administration's (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) has provided a favourable recommendation for GlaxoSmithKline's oral rotavirus candidate vaccine, Rotarix [rotavirus vaccine, live, oral], to prevent rotavirus gastroenteritis in infants.

The Committee voted unanimously (12-0) in favour of GSK's data being adequate to support the efficacy of the candidate vaccine. The Committee voted 11-1 in favour of GSK's data being adequate to support the safety of the candidate vaccine.

If approved by the FDA, GSK's candidate vaccine would allow for completion of the rotavirus vaccination series by four months of age and could be integrated into the current vaccine schedule at the two and four month immunization visits. Severe rotavirus diarrhea and dehydration can occur as young as three months of age. Of children under five years of age in the US hospitalised with rotavirus, approximately one in five are younger than six months of age. Rotavirus infects virtually every child in the US by age five and is the leading cause of severe gastroenteritis in infants and young children worldwide.

The candidate vaccine contains a live, weakened form of human rotavirus derived from the most common human rotavirus strain. "If approved, we believe Rotarix, which was developed to mimic the protective effects of natural infection, would offer an important option in completing rotavirus vaccination by four months of age," said Barbara Howe, M.D., vice president and director, North American Vaccine Development, GlaxoSmithKline. "Studies have shown that naturally occurring human rotavirus infection provides significant protection against subsequent moderate to severe rotavirus gastroenteritis regardless of the infecting serotype."

The committee's favourable recommendation, although not binding, will be considered by the FDA in its review of the Biologics License Application (BLA) for the candidate vaccine, which is currently underway.

Clinical data published on two doses of ROTARIX show that protection was sustained through the first two years of life and was highly efficacious against rotavirus hospitalizations (96 per cent) and severe rotavirus gastroenteritis (90 per cent). In addition, the candidate vaccine was effective against rotavirus gastroenteritis of any severity (79 per cent). Specifically, significant protection was demonstrated against severe rotavirus gastroenteritis during two rotavirus seasons caused by types G1 (96 per cent), G2 (86 per cent), G3 (94 per cent), G4 (95 per cent), and G9 (85 per cent), the most commonly circulating rotavirus types in the U.S.

The CDC Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP) recommend that infants receive routine vaccination with the rotavirus vaccine currently licensed by the FDA at two, four, and six months of age in order to prevent rotavirus gastroenteritis.

The GSK candidate rotavirus vaccine is an oral live-attenuated human rotavirus vaccine licensed in more than 100 countries around the world. The vaccine was developed to prevent rotavirus gastroenteritis by mimicking the protective effects of natural human rotavirus infection. Naturally occurring human rotavirus infection provides significant protection against subsequent moderate to severe rotavirus gastroenteritis regardless of the infecting serotype(s). Five phase III clinical trials were conducted worldwide to assess the safety and efficacy of GSK's rotavirus candidate vaccine in support of U.S. licensure. The BLA for the GSK rotavirus candidate vaccine is based on one of the largest clinical development plans undertaken by a vaccine manufacturer and includes data from nearly 75,000 infants. The clinical trials conducted in support of US licensure demonstrated efficacy against rotavirus gastroenteritis of any severity due to the five most common currently circulating rotavirus types. The most common solicited adverse reactions in clinical trials were fussiness/irritability, cough/runny nose, fever, loss of appetite, and vomiting.

Rotavirus infects virtually every child worldwide by age five and is the leading cause of severe gastroenteritis in infants and young children in the US and worldwide. Severe, dehydrating gastroenteritis can occur as young as three months of age. In the US each year, 2.7 million children younger than five years of age suffer from rotavirus disease, resulting in 410,000 clinic visits and up to 272,000 emergency room visits. In addition, between 55,000 and 70,000 children are hospitalised and 20-60 die each year. In the US, the rotavirus season typically begins in the southwest during November-December and spreads to the northeast by April-May.