The race to vaccinate the public against Covid-19 has entered its next phase and geopolitics are complicating the matter. There are several vaccines in circulation right now, but only two cleared for use in the EU. A shortage of vaccines across the bloc has been accompanied by high-level anger. A three-way row is on between the UK, the EU and supplier AstraZeneca, which says it cannot fulfil a 400-million-dose order for Brussels. Meanwhile, other countries are turning to Russia, China or India for their vaccines. What's being done to improve access for those in the developing world?