The race to secure a vaccine against COVID-19 has pitted country against country, which could undermine efforts to control the virus worldwide. While the World Health Organization is calling for those at highest risk of getting and spreading the virus to receive a vaccine first, rich countries are making deals to stockpile their own supplies — even before safe and effective vaccines exist — and that comes with risks. This kind of vaccine nationalism means every country fends for itself, with wealthier nations buying up supplies of vaccines and leaving little for other nations. Dr. Margaret Harris, a spokesperson for the World Health Organization, says vaccine nationalism is self-defeating in multiple ways: it will hinder the revival of the global economy and extend disruptions of world trade and travel.