Originally Posted by
goji
They don't need to explain who has been exposed to the virus, as by simple probabilities, it is very obvious that many people will be exposed. I'm surprised it's only 94 cases, since the US has about 330 million people and has had almost 10 million covid cases.
44,000 people in the trial
50% with the vaccine and 50% with the placebo.
8 infections in vaccine group of 22,000
86 infections in placebo group of 22,000
Conclusion: Vaccine is useful.
[Note: The 8 and 86 are working back from 90% effectiveness. I'm assuming the immunologists define 90% effectiveness in the obvious way. ]