Author Contributions: Dr Neuzil had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Neuzil, Canh, Thiem, Janmohamed, Huong, Tsu.
Acquisition of data: Canh, Thiem, Janmohamed, Huong, Diep, LaMontagne.
Analysis and interpretation of data: Neuzil, Janmohamed, Tang, LaMontagne.
Drafting of the manuscript: Neuzil, Thiem, Janmohamed, LaMontagne.
Critical revision of the manuscript for important intellectual content: Canh, Janmohamed, Huong, Tang, Diep, Tsu, LaMontagne.
Statistical analysis: Neuzil, Janmohamed, Tang.
Obtained funding: Tsu.
Administrative, technical, or material support: Canh, Thiem, Janmohamed, Huong, Tsu, LaMontagne.
Study supervision: Canh, Thiem, Janmohamed, Huong, Diep, Tsu, LaMontagne.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: This study was funded with a generous grant from the Bill & Melinda Gates Foundation. Merck & Co Inc provided the vaccine and the immunogenicity testing for no charge.
Role of the Sponsor: The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; or preparation, review, or approval of the manuscript.
Additional Contributions: We are grateful to the volunteers and their families for their participation in this study. We thank To Thanh Phuong, MD, former director of Hoa Binh Provincial Medical Center, Bui Dinh Thi Dinh, MD, former vice director of Hoa Binh Preventive Medical Center, the health staff of Hoa Binh and Kim Boi District Preventive Medical Centers, and the leaders and teachers of the 21 participating schools. We acknowledge the following persons for their invaluable assistance and support of the trial: Nguyen Tran Hien, MD, director (National Institute of Hygiene and Epidemiology), Dang Thi Mai, nurse, and Nguyen Hoang Anh, BPH (Division of Vaccine Clinical Trial, Department of Epidemiology, National Institute of Hygiene and Epidemiology, Ministry of Health, Hanoi, Vietnam); Nguyen Kim Loan, MD (Department of Laboratory, Hoa Binh Preventive Medical Center); Aisha Jumaan, PhD, John C. Victor, PhD, Colleen Kuehl, BA (PATH, Seattle, Washington) and Le Thi Nga, MD, and Trinh Thu Huong, BA (PATH, Hanoi, Vietnam). Dr Hien received no compensation for his efforts at the National Institute of Hygiene and Epidemiology in support of the study. All of the others listed in this section received compensation for their study-related activities.