1. World Health Organization, India-National Polio Surveillance Project, R. K. Khanna Stadium, Africa Avenue, Safdarjung Enclave, New Delhi 110029, India.
2. Enterovirus Research Center, Haffkine Institute Compound, Parel, Mumbai, India.
3. World Health Organization, Ave Appia, Geneva, Switzerland.
4. Panacea Biotec Ltd., New Delhi, India.
5. Centers for Disease Control and Prevention, Atlanta, GA, USA.
6. Department of Infectious Disease Epidemiology, Imperial College London, London, UK.