Three Barriers That Stand in the Way of Global Vaccination Evolutionary pressure on the virus will inevitably favour mutations that make the disease more transmissible, or the virus itself more vaccine-resistant. It is clear, therefore, that every nation’s interest is in universal vaccination. But this is not the trajectory we are on. We will not be able to put the COVID-19 pandemic behind us until the world’s population is mostly immune through vaccination or previous exposure to the disease. A truly global vaccination campaign, however, would look very different from what we are seeing now. For example, as of January 20, many more people have been immunised in Israel (with a population less than 10 million) than in Africa and Latin America combined.