1. Public Health Services, Israel Ministry of Health, Central Virology Laboratory, Sheba Medical Center, Tel Hashomer, Israel
2. Division of Virology, National Institute for Biological Standards and Control, Hertfordshire, United Kingdom
3. Polio and Picornavirus Laboratory Branch, Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
4. World Health Organization EUROPE, Regional Polio Laboratory Network, Copenhagen, Denmark
5. Ministry of Health, Jerusalem, Israel