In 2017, World Bank issued and sold up to $500 million of very high yield "pandemic bonds," due to mature on July 15, 2020. "If a pandemic did not occur before the bonds mature...investors would receive what they had originally paid in addition to interest and premium payments on those bonds." BUT the investors "would lose their money if any of six deadly pandemics hit, including coronavirus."
The pandemic would have to be global and officially recognized by the World Health Organization. Now that we have that pandemic, the bondholders will lose their money. WHO claims it will use these funds to fight the pandemic. Read more here.