1. Center for Vaccine Research, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania , USA
2. Department of Infectious Diseases and Microbiology, University of Pittsburgh School of Public Health , Pittsburgh, Pennsylvania , USA
3. Department of Pediatrics and the Department of Biomedical Informatics and Medical Education , University of Washington, Seattle, Washington , USA
4. Center for Global Infectious Disease Research, Seattle Children’s Research Institute , Seattle, Washington , USA