There are a few issues here. First note more importantly note that the barrier for "confirmed reinfection" here is far, far more strict here than the barrier for "confirmed cases in vaccinated individuals".<p>A "confirmed reinfection" for someone who previously had Covid requires them to have gotten sick, tested positive, have the virus sequenced, then later get sick, test positive, get the virus sequenced again, and have the sequences demonstrate that the infections were caused by distinct virus variants. This is because it is often impossible to tell if someone who appears to be reinfected is suffering from a relapse but never cleared the virus, is suffering from "long Covid", or otherwise falsely tested negative without fully recovering. The number of suspected reinfections is orders of magnitude higher than 72, simply because we don't sequence most positive cases, and even if we did, the chance of being infected by different variants is relatively low. Even in your tracker, it has a "suspected cases" for reinfections at nearly 40,000, which is likely a large estimate simply based on reporting gaps.<p>On the other hand, to be confirmed as a case after vaccination, you simply have to have been vaccinated, and then test positive. The bar here is far lower, so of course there will be more observed cases.<p>Lastly, immunity isn't some black box. We understand many of the biological components involved in how the immune system fights infection, in the form of IgA antibodies, IgG antibodies, T-cells, B-cells, etc. There have been numerous studies done over the last 6 months demonstrating that the presence of these immunity components is far higher for vaccinated individuals than those who simply have natural immunity.