Monday, 12 April 2021, 5:08 pm 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. What are the main challenges that need to be overcome, if this historic global effort is to be achieved? Vaccines are a key part of the solution to ending the COVID-19 pandemic and, since the early stages of the crisis, the World Health Organization (WHO) has argued that there needs to be a coordinated approach towards ensuring that everyone, not just people living in rich countries, receives