2012 Antigen review for the New Zealand National Immunisation Schedule: Rotavirus

Abstract

Rotaviruses are the leading cause of severe diarrhoeal illness in infants worldwide affecting virtually every child either in infancy or early childhood. Infections are most severe in infants three months to 24 months of age. Universal infant rotavirus vaccination programmes for all countries are recommended by the World Health Organization (WHO). Current rotavirus vaccines on the world market are live attenuated, and focused on the common human P and G serotypes. Two international vaccines are licensed in NZ: Rotarix® (RV1) is a live attenuated human rotavirus strain P1A[8]G1 and RotaTeq® (RV5) is a pentavalent human-bovine reassortment containing G types 1-4 (VP7) and P[8] (VP4). There are a range of other live attenuated rotavirus vaccines in the pipeline. In New Zealand (NZ) the third largest cause of potentially avoidable paediatric admissions to hospital is gastroenteritis (from all causes), preceded only by respiratory infections and asthma. Rotavirus gastroenteritis represents approximately 40% of the overall gastroenteritis hospitalisation burden. Rotavirus gastroenteritis is more common in children aged 12-35 months, followed by those six to 11 months and is less common in infants under six months. There is clear seasonality, with over half of cases occurring in winter/ spring. NZ data estimates of the burden of disease predict that by the age of five years, one in five children will have sought medical advice for rotavirus gastroenteritis, and one in 43 will have been hospitalised. Mortality is very rare. The predominant NZ circulating strain is G1, followed by G4 which is similar to the European and United States (US) pattern. However, NZ has significant regional differences and rarer strains have been identified, highlighting the importance of on-going surveillance.