Yeah 95% efficacy is the important data. The reduction in covid rate of 0.7% is a bit misleading as it doesn't capture scaling and the knock on effect of having fewer cases in the community which reduces the r rate etc. That's why scientists use efficacy as the truest measure of a vaccine.
Is there methodology used to understand the effects of vaccines, they hardly ignore it and it must be an important variable.
Edit; not in the trials but in the general population.
That’s correct. I explained
here, how Pfizer arrived at the efficacy rate, i.e., by dividing 0.70 by the infection rate of the placebo group, 0.74% = 95%.
The efficacy rate, while truly remarkable, is theoretic rather than an absolute. It is the rate that would be expected if the people and conditions in the clinical trial exactly mirrored real world.
Real world effectiveness can be higher or lower depending on prevailing conditions such as attack rates, variants, underlying illnesses, behaviour, exposure, transmissibility, vaccine availability & uptake, etc.
They will vary from country to country and areas within countries.
Vaccine effectiveness is discovered during its rollout in the real world by observation, data collection and study and this is going on worldwide.
And that is what NPHET and its contributors do all day every day in the Irish context.
Doubtless their work was and continues to be obstructed by the cyber-attack on the HSE’s IT systems.
Israel, which is more on with vaccinations than other countries, has put a lot of work into analysing real-world vaccine effect -
here.
But as you can see, because the real world cannot be controlled in the same way as in a clinical trial, analysis can be tortuous.