Progress toward interruption of wild poliovirus transmission–worldwide, January 2006-May 2007

Progress toward global polio eradication continued during 2006 and the first 5 months of 2007, although the number of countries where wild poliovirus (WPV) transmission has never been interrupted remained at four (Afghanistan, India, Nigeria, and Pakistan). Continuing challenges included intense WPV circulation in northern India during 2006, low vaccination coverage with oral polio vaccine (OPV) during supplemental immunization activities (SIAs) in Nigeria, and security problems preventing access to children during SIAs along the Afghanistan-Pakistan border. Programmatic strategies to address these challenges consisted of large-scale use of type 1 monovalent oral polio vaccine (mOPV1), targeted programs (e.g., cross-border synchronization of polio campaigns) to reach more children through SIAs, and introduction of new laboratory procedures to confirm cases more rapidly. This report summarizes these strategies and overall progress toward global polio eradication.