Differences of Rotavirus Vaccine Effectiveness by Country: Likely Causes and Contributing Factors
Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK
Pathogens 2017, 6(4), 65; https://doi.org/10.3390/pathogens6040065
Received: 20 September 2017 / Revised: 5 November 2017 / Accepted: 7 November 2017 / Published: 12 December 2017
(This article belongs to the Special Issue Rotavirus Epidemiology: Host, Climate and Vaccine Influences)
Rotaviruses are a major cause of acute gastroenteritis in infants and young children worldwide and in many other mammalian and avian host species. Since 2006, two live-attenuated rotavirus vaccines, Rotarix® and RotaTeq®, have been licensed in >100 countries and are applied as part of extended program of vaccination (EPI) schemes of childhood vaccinations. Whereas the vaccines have been highly effective in high-income countries, they were shown to be considerably less potent in low- and middle-income countries. Rotavirus-associated disease was still the cause of death in >200,000 children of <5 years of age worldwide in 2013, and the mortality is concentrated in countries of sub-Saharan Africa and S.E. Asia. Various factors that have been identified or suggested as being involved in the differences of rotavirus vaccine effectiveness are reviewed here. Recognition of these factors will help to achieve gradual worldwide improvement of rotavirus vaccine effectiveness.