As the northern hemisphere summer approaches, governments are racing to unlock travel. Several countries have introduced systems they hope will allow the tourism economy to restart safely. But the EU is one of only a few regions where this is possible. Nearly four out of 10 people in the bloc have had at least one shot of the Covid-19 vaccine. Meanwhile, other regions around the world are struggling to vaccinate even the most vulnerable — a fact the World Health Organization has called a “moral outrage”.