1. Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27705, USA.
2. Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA.
3. Department of Pediatrics, University of Alabama of Birmingham, Birmingham, AL 35233, USA.
4. Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA.
5. Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
6. Merck & Co. Inc., Kenilworth, NJ 07033, USA.
7. Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center, Houston, TX 77030, USA.
8. Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27705, USA.
9. Department of Pediatrics, Duke University Medical Center, Durham, NC 27705, USA.