So at some point the effectiveness of the vaccine could drop to as low as zero.At the moment there is no sustainable long term vax program to hold out from. The only evidence we have is that the vaccines are short term... with reduced efficacy over time and reduced efficacy to new variants.
Why would we even suspect the boosters will stay ahead of the variants?
This is new science.
Vaccinating in the middle of a pandemic with a partially effective vaccine which does not wipe out the virus.
This is very dangerous ground... no expert can speak of long term.
The long term variant production is unquantifiable.
At that point are vaccine passports valid, do they make sense?