Performance of rotavirus vaccines in developed and developing countries

Abstract

The World Health Organization estimates that rotavirus diarrhea results in approximately half a million deaths and approximately 2.4 million hospitalizations in developing countries each year. Two live oral rotavirus vaccines, RotaTeq© (RV5; Merck) and Rotarix© (RV1; GlaxoSmithKline) with good efficacy against severe rotavirus disease and a reassuring safety profile could substantially impact the burden of rotavirus disease. In April 2009, WHO provided a recommendation for global introduction of these vaccines in national immunization programs of developing countries worldwide. In this article, we review published data on previous candidate rotavirus vaccines and vaccines in current use, with emphasis on their performance in developed versus developing countries. In developed countries, both first and second generation rotavirus vaccines have demonstrated high efficacy against severe rotavirus disease (pooled efficacy = 73% and 85%, respectively). In developing countries, small early trials for the first generation vaccines failed to provide protection against rotavirus disease (pooled efficacy = 20%), however, trials of the second generation vaccines yielded substantial improvements in efficacy in developing countries (pooled efficacy of 51%), leading to a global recommendation for rotavirus vaccine introduction by WHO. Future efforts for these vaccines should focus on optimizing the efficacy and delivery of these vaccines in challenging target populations of Asia and Africa with the greatest burden of severe rotavirus disease.

Figures and Tables

Figure 1 Pooled estimates of efficacy against severe rotavirus disease by income settings for first and second generation rotavirus vaccines. These estimates are the pooled estimates and 95% confidence limits are generated from studies outlined in Tables 2 and 3 (refer to Methods).

Table 1 Past or current rotavirus vaccines with efficacy data from clinical trials

Table 2 Review of clinical trials of efficacy for first generation rotavirus vaccines

Table 3 Review of clinical trials of efficacy for second generation rotavirus vaccines

Table 4 Postlicensure studies assessing effectivenes of Rotarix (RI X-4414) and RotaTeq (WC3)

Table 5 Studies of rotavirus vaccines assessing duration of protection of second generation rotavirus vaccines against severe rotavirus diarrhea