The Pfizer vaccine is estimated to be 90% effective (UK rollout of Covid vaccine could start before Christmas, 9 November) and the UK has ordered 40m doses, enough to immunise 20 million vulnerable people, and therefore protect 18 million of them. To protect those people and save lives, we need a smooth supply chain for highly refrigerated medication imported from Belgium and Germany. But the Brexit transition period is due to terminate on 31 December, without any prospect of inbound logistics running smoothly. To support this vaccination programme, an emergency application should be made to extend the transition period. I expect the EU would, in the circumstances, look favourably on this. Which is more important: failed Brexit ideology, or saving lives? Mike Cashman Milton Keynes, Buckinghamshire • The National Audit Office report (UK-EU trade faces major disruption even with deal, say auditors, 6 November) documents a range of risks about UK readiness for the 1 January exit. These include snags with new IT systems, delays in preparation at customs sites and sites in Kent for traffic management. At Dover, there could be queues of up to 7,000 lorries. The report, however, has no discussion of another looming risk – from Covid-19. Thousands of drivers will be having to find the new sites and may have to wait for hours. There will be a high risk of the virus super spreading. Testing will be essential, as will be coordination with port staff in France and Belgium. The NAO report also ignores the knock-on effects of delays backing up in the UK, from new systems across the Channel. The health risks could lead to a complete failure of the new systems as many drivers become infected. There is now a strong case for seeking an agreement with the EU to continue trading on existing terms for six months. This will give time for proper testing on new IT systems, full site preparation and health coordination. On the present course there is a high risk of a mega disaster with blockage of vita supplies for weeks. Nick Bosanquet Professor of health policy, Imperial College London • Polly Toynbee could have mentioned in her article (With Biden elected, a no-deal Brexit would make Britain a pariah. It can’t happen, 10 November) that, according to evidence given on Monday to a House of Lords committee, the new customs declaration system will not be ready for 1 January. What is striking is the lack of liaison between HMRC and its counterparts in other EU countries. When I worked in HM Customs and Excise, there was good inter-state coordination, but now that the UK has left the EU, such co-working has ceased. British business will have to suffer from the consequences of the government’s inept handling of Brexit. Ian Arnott Werrington, Peterborough • Polly Toynbee emphasises the inevitable disruption when we finally leave the EU on 31 December, due to our total lack of preparation. But is this inevitable? At the moment, there are no lorry queues at the channel ports, food shelves are not empty, and whatever paperwork is needed for the normal operation of trade under the EU is in place and working. Let us maintain this state of affairs after 31 December by, in agreement with the EU, putting off our final departure until 31 December 2021. And as December 2021 approaches, we can avoid a similar problem by putting off our departure until 31 December 2022. John Williams London