Although this study was undertaken to reflect some of the conditions of

routine vaccine use, it will be important to examine vaccine performance when used in the childhood immunisation programme in Malawi. Vaccine effectiveness using a two-dose schedule of Rotarix administered at 6 and 10 weeks of age (the schedule recommended by WHO but not previously evaluated in a clinical trial) is being investigated in an effectiveness trial in Bangladesh (www.clinicaltrials.gov). The relationship between vaccine performance and age of administration also needs further assessment, in order to better understand the duration of protection provided by a two-dose schedule. Furthermore, although the vaccine efficacy (individual Etoposide supplier protection) in this clinical trial was relatively modest, the potential for an additive, indirect population benefit of vaccination is highlighted by recent experience from industrialised countries where greater than anticipated reductions in disease burden have been documented [41]. The protection provided by RIX4414 against severe rotavirus

gastroenteritis in an impoverished African population is a major advance in the effort to reduce the global burden of rotavirus disease, over 20 years since clinical trials of early generation rotavirus vaccines IOX1 clinical trial undertaken in Africa failed to demonstrate an impact on rotavirus gastroenteritis (reviewed in [35]). Preliminary health economic analyses support the introduction of rotavirus vaccines in Malawi [42]. Introduction of this life-saving vaccine into Malawi and other countries with high rotavirus disease burden is urgently needed. We thank the parents/guardians and the children for their participation. We thank Dr. Mark Goodall and Mr. Joseph Fulakeza for laboratory management in Malawi, together with the “Rotavaccine” Clinical Trial

team. We thank Professor Robin Broadhead for his advice, support and encouragement. We acknowledge DDL Diagnostic Laboratory, The Netherlands Methisazone for determining rotavirus G and types. We acknowledge the GSK team for their contribution in review of this paper. Rotarix is the trademark of GlaxoSmithKline group of companies; RotaTeq is the trademark of Merck & Co., Inc; Rotaclone is a trademark of Meridian Biosciences, Cincinnati, OH. The clinical trial was funded and coordinated by GSK and PATH’s Rotavirus Vaccine Program, a collaboration with WHO and the US Centres for Disease Control and Prevention, with support from the GAVI Alliance. Contributors: Nigel Cunliffe was the principle investigator of this study. The Malawi-based investigator team of Desiree Witte, Bagrey Ngwira, Stacy Todd, Nancy Bostock, Ann Turner, and Philips Chimpeni supervised enrolment and follow-up of subjects and collection of clinical data.