Chapter 2.11 - Rotavirus Vaccines and Vaccination

Abstract

Two live oral rotavirus (RV) vaccines, a human attenuated G1[8] RV strain and a bovine-human reassortant five component combination vaccine, were licensed in 2006, and in the next several years universal RV vaccination of all healthy infants was introduced in most Latin American countries, the United States, Australia, South Africa, and several European countries. More recently RV vaccination with GAVI support has been integrated into EPI programs of many African and other developing countries. In addition, locally produced live oral lamb RV vaccine is being used in China, and human RV strain vaccines are being launched in India and Vietnam. Altogether, universal RV vaccination has been introduced in about 80 countries, and the global experience has shown that RV gastroenteritis is a vaccine preventable disease. Live oral RV vaccines prevent effectively severe RV disease but have little effect on RV infection as such. In Finland, representing optimal conditions, the real life effectiveness against RV associated hospitalizations has been 95%, in Latin America around 80% and in Africa between 50% and 70%. The mechanism of protective immunity is not fully understood, but it is likely that much of the protection against severe RV disease is not serotype-specific but mediated by immunity against the inner core major protein and group antigen VP6. The lower effectiveness in developing countries is due to several reasons not easily remedied. All live oral RV vaccines appear to be associated with a (low) risk of intussusception (IS). Risk of IS and less than optimal effectiveness in developing countries are the main drivers towards development of nonlive candidate RV vaccines.