Originally Posted by
43Inches
AZ at present has a 63% efficacy rating ...
What is your source for that please?
As this diagram illustrates there are multiple points at which efficacy can be measured; some are more important than others.
Source: What defines an efficacious COVID-19 vaccine? A review of the challenges assessing the clinical efficacy of vaccines against SARS-CoV-2. Hodgson et al