The World Health Organization has approved the coronavirus vaccine developed by AstraZeneca. It will be a boost for poorer countries where millions of doses are set to be distributed. The AstraZeneca shot, which is easier to store and transport than some of its rivals, will account for almost all the doses set to be shipped under Covax, an international programme designed to ensure that poor countries do not miss out. While inoculation drives have been gaining pace, with nearly 172 million vaccine doses given worldwide, most of the jabs have so far gone to richer countries.