The United States has, with little fanfare, become the largest financial donor to COVID-19 Vaccines Global Access (COVAX). It is working with allies and partners, such as the Quadrilateral Security Dialogue (known as the Quad), to develop creative approaches to manufacturing and distributing vaccines globally. As the Quad vaccine initiative shows, the United States is now tackling vaccine diplomacy in a way that strengthens cooperation among countries threatened by China’s rise without being overtly confrontational toward China. More of this will, presumably, be coming—and sooner rather than later. What some analysts thought might be possible by the end of 2021—an ambitious program to produce and globally distribute U.S.-made vaccines—could be feasible by late summer or early fall. China, by contrast, will soon find itself at a disadvantage. The fact that Chinese companies used a relatively unsophisticated approach to making vaccines and, in some cases, carried out clinical trials abroad meant that Beijing could quickly promise jabs to other countries. Yet the number of vaccines delivered has fallen well short of the number promised while nagging doubts about the efficacy of Chinese vaccines are dampening their appeal. In the United Arab Emirates, some Sinopharm vaccine recipients have been given third doses because the first two didn’t do the trick. The government of Singapore has opted to leave Chinese-made vaccines in storage for now and rely on Western alternatives. And residents of Hong Kong are showing a distinct lack of enthusiasm for Chinese jabs. Reports that Beijing has sought to strongarm vaccine supplicants into making diplomatic concessions—such as Paraguay distancing itself from Taiwan—also indicate that China may struggle to win much goodwill, even if it does use some coercive leverage. As unlikely as it might have sounded just a few months ago, the United States still has a good chance to be the country that leads the world out of the pandemic—an opportunity that, if Washington can seize it, would surely cause the world to rethink who “won” the crisis after all.