Currently there is a difference between the designs of the stage 3 trials of the three leading vaccines.
The two messenger RNA vaccines were only evaluated by symptoms, not actual testing for the virus. The results are in the 90+% range.
The Oxford/AstraZeneca vaccine trial involved testing each participant weekly. The results are in the 70% range.
Because the trials were designed differently, the old apples/oranges comparisons are at work. And because of the different trial protocols, we don’t know really anything about if or for how long a vaccinated person may eventually become infectious without themselves ever getting sick.
Eventually these unknowns may prompt a rethink at the national level about compelling people to get vaccinated.
Currently about 70% of people aim to get vaccinated. If the vaccine is 70% effective at preventing infections, that still leaves about 50% of the population at risk, although with a reduced infection rate owing to at least partial herd immunity.