The US Food and Drug Administration has released information on the BoiNtech/Pfizer coronavirus vaccine ahead of its meeting to consider emergency certification in the USA. It is noteworthy that the definition of a "case" is quite different from that used for the Oxford/AstraZeneca vaccine so that the claimed efficacies are not comparable. For the BioNtech/Pfizer vaccine a swab is taken when an acute respiratory illness develops. For the Oxford/AstraZeneca vaccine weekly swabs are taken. These are clearly different and will result in spurious lower apparent efficacy for the Oxford/AstraZeneca vaccine.