Science
24 April 2020 Vol 368, Issue 6489
http://www.sciencemag.org/current.dtl

Evolving epidemiology of poliovirus serotype 2 following withdrawal of the serotype 2 oral poliovirus vaccine
By G. R. Macklin, K. M. O’Reilly, N. C. Grassly, W. J. Edmunds, O. Mach, R. Santhana Gopala Krishnan, A. Voorman, J. F. Vertefeuille, J. Abdelwahab, N. Gumede, A. Goel, S. Sosler, J. Sever, A. S. Bandyopadhyay, M. A. Pallansch, R. Nandy, P. Mkanda, O. M. Diop, R. W. Sutter

Science24 Apr 2020 : 401-405 Full Access
Outbreaks of serotype 2 vaccine-derived poliovirus can be traced to use of the oral poliovirus vaccine in outbreak response campaigns.