Where will poorer countries stand in the queue for a Covid-19 vaccine? | Clare Wenham and Mark Eccleston-Turner

The lion's share of the potential Pfizer vaccine is already claimed by high-income nations

The news that joint efforts by the US pharmaceutical company Pfizer and the German biotech company BioNtech have produced a vaccine that is 90% effective at protecting people from Covid-19 has been understandably applauded - in spite of the caveats. Pfizer states that it can manufacture up to 50m doses by the end of 2020 and up to 1.3bn doses in 2021.

Given the desire to get life back to normal, these doses will be in incredibly high demand. Some governments around the world, including the UK, have already begun to indicate to their populations that they will receive a vaccine by Christmas. But how will the distribution of this finite number of vaccines work when we only have enough for one seventh of the global population?