Systematic Literature Review

We performed a systematic search of the PubMed and Cochrane databases for peer-reviewed articles published from January 1, 2006, to July 7, 2016, using prespecified terms related to RV vaccines, as detailed in the Supplementary Data. We included papers in any language reporting data from postlicensure or original studies assessing the VE of Rotarix (full inclusion and exclusion criteria are presented in the Supplementary Data).

Relevant references were selected by a 3-step selection procedure. First, titles and abstracts identified through the search were screened based on their relevance to the objectives, with a random sample of 30% of titles and abstracts being screened in duplicate. Second, a full-text review of articles selected during the first step was performed, with the first 10% of the articles being appraised by 2 reviewers. Third, further scrutiny of the articles during the data extraction phase was applied. For example, when 2 included articles described results of the same study, we only included 1 of the articles in the meta-analysis to avoid double inclusion of data (ie, the article published most recently or with the most relevant data). In addition, the reference list of meta-analyses or systematic reviews was checked for relevant articles that could have been missed. The quality of the selected articles was assessed using the Coordination of Cancer Clinical Practice Guidelines (CoCanCPG) [15].

We extracted and summarized the following data as a minimum: study design, setting and period, study objectives, study country and its socioeconomic status (SES; according to the World Bank list of economies classification [16]), type of control group used (matched/unmatched hospital, test-negative, community/neighborhood controls), clinical setting (hospitalizations or ED visits), RV strain type (homotypic, fully/partly heterotypic), disease severity (mild, moderate, severe, and very severe, according to the Vesikari score list [17]), reports on vaccine introduction in the NIP, and vaccination coverage, when available.