1 Department of International Health, The Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD, 21205, USA. rosepollard@jhu.edu.
2 Division of Infectious Diseases, The Johns Hopkins University School of Medicine, 1830 E. Monument St, Baltimore, MD, 21205, USA.
3 International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, 415 N Washington St, Baltimore, MD, 21231, USA.
4 Y.R. Gaitonde Centre for AIDS Research and Education (YRG CARE), 58 Harrington Road, Chetput, Chennai, 600031, India.
5 Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD, 21205, USA.
6 Department of International Health, The Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD, 21205, USA.