This means all possible vaccination schedules involving the Oxford-AstraZeneca and Pfizer-BioNTech vaccines could potentially be used against COVID-19. ‘The results show that when given at a four-week interval both mixed schedules induce an immune response that is above the threshold set by the standard schedule of the Oxford/AstraZeneca vaccine. The highest antibody response was seen after the two-dose Pfizer-BioNTech schedule, and the highest T cell response from Oxford-AstraZeneca followed by Pfizer-BioNTech. Deputy Chief Medical Officer Professor Jonathan Van-Tam said: ‘Today’s data are a vital step forward, showing a mixed schedule gives people protective immunity against COVID-19 after four weeks. Given the UK’s stable supply position there is no reason to change vaccine schedules at this moment in time.
