The widespread implementation of live rotavirus vaccines of differing designs since 2006 has provided the opportunity to explore the clinical impact and epidemiology of rotavirus, confirming much previous understanding but also challenging accepted evidence. The introduction of monovalent, live attenuated, human rotavirus vaccine RV1 (Rotarix, GSK Biologicals) and pentavalent bovine-human reassortant RV5 (Merck Vaccines) in developed and developing settings has allowed the examination of serotype epidemiology, herd immunity and intussusception. Effectiveness data have confirmed natural history data regarding individual protection against subsequent rotaviral diseases, but highlighted further challenges in developing settings in both immunogenicity and efficacy. These offer insights into the role of breast milk, passive immunity and gut microbiome in the ability for rotavirus to establish infection. Despite nearly 7 years surveillance post-implementation in some settings, there had been little evidence to date of serotype replacement due to vaccine pressure, or vaccine escape strains.
The association with intussusception of all rotavirus vaccines licensed and implemented into national immunisation programs to date after first and/or second doses, is confronting to the weight of epidemiological and case-control data arguing against a role for wild-type rotavirus in the pathogenesis of intussusception, the most common cause of acute bowel obstruction in early childhood.