Rotaviruses

Abstract Rotaviruses are infectious agents, transmitted by the faecal–oral route. Distinguishing features include a genome consisting of 11 segments of double‐stranded ribonucleic acid (dsRNA), distinctive morphological appearance by electron microscopy and unique morphogenesis involving transient lipid‐enveloped particles. Primary rotavirus infections in the young of mammals and birds can cause severe diarrhoea after replication in the small intestine. Reinfections result in protective immune responses. Worldwide morbidity and mortality rates in children justify vaccination to protect against this disease. Two safe live oral rotavirus vaccines, based on either a single attenuated human rotavirus strain, or a pentavalent mixture of human–bovine rotavirus reassortants, are now licensed and in use in many countries. Both are immunogenic and highly efficacious in prevention of severe rotavirus diarrhoea in children in developed countries. Recent trials have demonstrated lower vaccine efficacy in children in Africa and Asia. WHO has recommended the universal use of both vaccines. Key Concepts: An estimated 4.6 million people, including 2.5 million children, die from diarrhoea every year particularly in developing countries. Worldwide, rotavirus is the major cause of infectious diarrhoea, particularly among young children. There have been major efforts to produce safe, effective and affordable rotavirus vaccines for worldwide use. The recent licensing of two human rotavirus vaccines provides optimism for controlling rotavirus disease.