1. Tel Aviv District Health Office, Ministry of Health, Tel Aviv, Israel
2. National Centre for Measles, Mumps, and Rubella, Central Virology Laboratory, Ministry of Health, The Chaim Sheba Medical Centre, Tel Hashomer, Israel
3. School of Public Health, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
4. Central Virology Laboratory, Ministry of Health, The Chaim Sheba Medical Centre, Tel Hashomer, Israel