The aim of the UN-backed COVAX scheme is to get two billion vaccine doses into the arms of around a quarter of the population of poorer countries by the end of 2021; however, some main challenges need to be overcome if this historic global effort is to be achieved. Here are five things to know about the challenges facing COVAX, and how they can be overcome. First is export controls. Early on in the pandemic, UNICEF built up a stockpile of half a billion syringes in warehouses outside the countries producing them. Its foresight paid off: countries put export controls on syringes, prices spiked, and supplies were limited. Several countries also placed export controls on vaccines, prompting WHO to warn against “vaccine nationalism”, which encourages hoarding, and has the effect of pushing prices up and ultimately prolonging the pandemic, the restrictions needed to contain it, and human and economic suffering. Second, getting vaccines to those who need it is not easy. Whilst all of the countries that are part of COVAX have the infrastructure needed to get pallets of vaccines off cargo planes and into refrigerated warehouses, the next steps can be more complicated. “Ghana, the first country to receive COVAX doses, has had a good record of distributing doses”, says Gian Gandhi, UNICEF’s global COVAX coordinator, “but other countries, such as those in Francophone West Africa, have found it difficult to muster the resources needed to divide up doses and distribute them throughout their territory to the towns and villages where they’re needed. This means that, in many poorer countries, most doses are being distributed in large urban centres”. Third, more funding is needed to help rollout in the poorest countries. One way to speed up the vaccine rollout, and the delivery from urban warehouses to remote areas is, quite simply, cash. UNICEF estimates that an additional $2 billion is needed to help the poorest 92 countries to pay for essentials such as fridges, health worker training, expenses for vaccinators, and fuel for the refrigerated delivery trucks, and is calling on donors to make $510m of this available immediately as part of a humanitarian appeal to address urgent needs. Fourth, richer countries should share. COVAX is finding itself in competition with individual countries doing direct deals with pharmaceutical companies, putting extra pressure on the available supply of COVID-19 vaccines. At the same time, richer countries may find themselves with an over-supply of doses. “We’re calling on these countries to share their excess doses, and engage with COVAX and UNICEF as soon as possible”, says Gandhi, “because it will take some legal, administrative and operational gymnastics to get them to where they’re needed. Unfortunately, we’re not currently seeing too many high-income countries willing to share”. Fifth is vaccine hesitancy that has been a continued cause for concern. Despite the overwhelming evidence that vaccination saves lives, vaccine hesitancy, which exists in every country, is still a problem that needs to be constantly addressed. This phenomenon is partly driven by misinformation surrounding all aspects of Covid-19, which was a concern even before a global health emergency was declared and, in May, the UN launched the Verified campaign, which fights lies and distorted messages, with trusted, accurate information surrounding the crisis.