| > you should conclude that the vaccine increases the risk of hospitalisation. Not really. It just means that since in that scenario the vast majority of people are vaccinated the break-through cases (people who despite being vaccinated end up hospitalised) outnumbers the small percentage of unvaccinated people who end up hospitalised *despite* the fact that the vaccine efficacy rate remains constant. I'm not sure if we're talking past each other, so let me take one step back and make another attempt: I made an extreme example to make it easy to see. Let's make an even more extreme example without any numbers nor percentages: Let's imagine that everyone, literally every single person in a population gets vaccinated. How many hospitalised people do you expect to see? Since the vaccine is not perfect and some people get severely sick despite the vaccine, you'd expect to see some number of hospitalised people. How many of those hospitalised people would be vaccinated? Well, we just said that in this scenario everybody in the population has been vaccinated, thus everybody who got hospitalised is vaccinated! Can we conclude that vaccines cause hospitalization? We clearly cannot conclude that from these numbers alone. Can we agree on this before continuing to talk about which crucial metric we're ignoring in this discussion? |