Could polio be poised for a comeback?

A health worker in Karachi administers polio drops — the oral vaccine — on February 3, the first day of a nationwide polio vaccination campaign. The country, one of only two where wild polio circulates, has seen a rise in cases due to issues with vaccination campaigns.

Cases have been rising in Afghanistan and Pakistan — and global health specialists are worried that this year's U.S. foreign aid cuts could usher in a wider resurgence.

(Image credit: Asif Hassan)