1. Polio this week — as of 15 September 2016. Geneva: Global Polio Eradication Initiative. Available from: http://www.polioeradication.org/dataandmonitoring/poliothisweek.aspx; [accessed 26.04.16].
2. World Health Organization. Position paper on poliovirus vaccines. WHO, Geneva, 25 March 2016. Available from: http://www.who.int/wer/2016/wer9112.pdf?ua=1; [accessed 07.06.16].
3. Immunisation against poliomyelitis: moving forward;Ehrenfeld;Lancet,2008
4. New generation of inactivated poliovirus vaccines for universal immunization after eradication of poliomyelitis;Chumakov;Clin Infect Dis,2008
5. UNICEF Supply Division – Inactivated poliovirus vaccine supply alert, May 2016. Available from: http://www.unicef.org/supply/files/IPV_no._5_Supply_Alert_Update.pdf; [accessed 07.06.16].