This week’s World Health Organization annual meeting could highlight tensions between global development efforts of a COVID-19 vaccine and the Trump administration’s U.S.-first, go-it-alone approach. The meeting also will offer insights into the approaches world leaders are taking to fight the pandemic: China is trying to gain more influence over the WHO, while the United States isolates itself and tries to develop a vaccine before the rest of the world. It’s not clear how the outcome of that race will...