If we report the vaccine is 99.5% effective at preventing serious illness, people will not listen to ANYTHING about being cautious and wearing a mask after they are vaccinated. I predict a nasty wave of COVID this fall/winter including in relatively highly vaccinated areas due to just this attitude already.
Uhm, the CDC literally told vaccinated people they don't need masks indoors or outdoors. [1] At that point it's kind of silly to say quoting 99.5% does or will a detrimental impact.
> I predict a nasty wave of COVID this fall/winter including in relatively highly vaccinated areas due to just this attitude already.
No; if it happens, it certainly wouldn't be due to this; at best ('best' for your argument), it would be due to their overriding guidance re: not wearing masks, which I mentioned above. However, I predict if this happens, it'll be due to changing circumstances like worse variants breaking through the vaccine (which the CDC admits they do not have sufficient data on [2]), not due to their current advice being bad due for current variants.
[1] https://www.webmd.com/lung/news/20210513/cdc-vaccinated-you-...
[2] https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vac...
You stated that the current form of measurement was not very good. I pointed out that we care about transmission and mutation for long term eradication of the disease - hence the measurement that is used. It's obviously not negligible or the entire professional world would not use it as a measuring stick for vaccine effectiveness.