Polio eradication this week:   

• From the 17 April to the 1 May, 155 countries and territories participated in the historic trivalent to bivalent oral polio vaccine switch, withdrawing the type two component of the vaccine to protect future generations against circulating vaccine derived polioviruses. Track the switch live.

• Preparing for the WHA: next week, health ministers from around the world will convene in Geneva for the annual World Health Assembly (WHA). Among other public health topics, delegates will review and discuss the latest global polio epidemiology. The GPEI has set up a WHA-specific polio website, with key documents to help guide discussions.