Prevention of rotavirus gastroenteritis in infants and children: rotavirus vaccine safety, efficacy, and potential impact of vaccines

Abstract

Rotavirus infection is the most common cause of severe gastroenteritis globally, with greater than 86% of deaths occurring in low-income and middle-income countries. There are two rotavirus vaccines currently licensed in the United States and prequalified by the World Health Organization. RV1 is a monovalent attenuated human rotavirus strain, given orally in two doses. RV5 is a pentavalent human-bovine reassortant rotavirus vaccine, given orally in three doses. A third rotavirus vaccine, LLV, is a lamb rotavirus strain given orally as a single dose, which is currently available only in China. RV1 and RV5 have been shown to be highly efficacious in developed countries, and initial results from trials in Africa and Asia are promising as well. At least three other vaccines are in development, which are being developed by manufacturers of developing countries. Further studies are needed to clarify issues including administration of oral rotavirus vaccines with breastfeeding and other oral vaccines, and alterations in dosing schedule. Using new data on global diarrheal burden, rotavirus is estimated to cause 390,000 deaths in children younger than 5 years. Should rotavirus vaccines be introduced in the routine immunization programs of all countries, a potential of 170,000 deaths could be prevented annually. The largest impact on mortality would be seen in low-income and middle-income countries, despite poor immunization coverage and lower efficacy. Therefore, international efforts are needed to ensure that rotavirus vaccines reach the populations with highest burden of rotavirus disease.

Keywords: gastroenteritis; mortality; rotavirus; vaccination.

Figure 1

Comparison of vaccine efficacy and effectiveness estimations from clinical trials of RV1 and RV5 against any serotype severe rotavirus gastroenteritis, stratified by country income status. Note: Efficacies and effectiveness estimates are taken from the following sources (from left to right): Asia, USA, Europe, Europe, Israel, Finland, Australia, USA, Latin America, Brazil, Finland/Latin America, South Africa, El Salvador, Nicaragua, Sub-Saharan Africa and Southeast Asia, Malawi. ^aThis study took place in a native population characterized by diarrheal pathogens that are similar to lower income settings. ^bAlthough countries ranged from lower middle to high income, most study countries are from the upper middle income category.

Figure 2

Estimated distribution of deaths caused by rotavirus diarrhea among children aged younger than 5 years.

Figure 3

Estimated incidence of deaths caused by rotavirus diarrhea per 100,000 children aged younger than 5 years.

Figure 4

Total deaths prevented by rotavirus vaccine in children aged under 5 years if introduced at level of DTP-3.

Figure 5

Total deaths prevented by rotavirus vaccine per 100,000 children aged younger than 5 years if introduced at level of DTP-3.

Figure 6

Global status of routine introduction of rotavirus vaccination.