The UK has ordered five million doses of vaccine from the US company Moderna and 40 million of the Pfizer jab. Moderna said its vaccine may be 94.5% effective against the virus, while Pfizer suggested theirs had an efficacy of 90%. Both vaccines use the same technology which gives the vaccinated person’s body the genetic instructions for their own cells to produce the antigens and generate an immune response. The trials are ongoing and final numbers could change. Moderna vaccine is much easier to distribute than the Pfizer jab which must be kept at -100C to maintain optimal efficacy causing concerns around the storage. The Moderna vaccine lasts 30 days in household fridges, 12 hours at room temperature and remains stable at -20C (equal to most freezers) for six months. The choice has been complicated by an announcement on 19 November that the vaccine being developed by Oxford University could be ready for use by Christmas. See