[1] Sabin Vaccine Inst, Appl Epidemiol, Washington, DC USA
[2] Stanford Univ, Stanford, CA 94305 USA
[3] Dhaka Shishu Hosp, Child Hlth Res Fdn, Dept Microbiol, Dhaka, Bangladesh
[4] Aga Khan Univ, Karachi, Pakistan
[5] Dhaka Shishu Hosp, Bangladesh Inst Child Hlth, Dhaka, Bangladesh
[6] Kathmandu Univ Hosp, Dhulikhel Hosp, Dhulikhel, Nepal
[7] US Ctr Dis Control & Prevent, Global Immunizat Div, Atlanta, GA USA
[8] Ctr Dis Control & Prevent, Natl Fdn, Atlanta, GA USA
[9] Univ Toronto, Dept Med, Div Infect Dis, Toronto, ON, Canada