The vaccine development process and coordination between health organizations have improved since a devastating 2014-2016 outbreak.

Uganda said that flights to and from the Democratic Republic of Congo would be temporarily suspended, as the outbreak appeared to spread to a rebel-controlled province in Congo.

A once-robust H.I.V. treatment and prevention system, credited with saving hundreds of thousands of lives, has begun to crumble.

The Trump administration had options for offloading contraceptives once destined for Africa, a newly obtained memo shows. Instead, it has let them collect dust and go bad.