That's a little terse, but I think it does point towards a valid observation about how people's expectations have had to change. It's gone something like this:
* Once we've been vaccinated, life will go back to normal.
* Well, okay, vaccination requires two separate doses.
* Of course we'll need an annual booster, like flu.
* Actually your certificate will only be valid for 9 months. (EU)
* Did I say 9 months? Better make it 6. (Israel)
* "the minimum gap between the second vaccine dose and booster should be reduced from six to three months." <--- You are here
We're not yet at the stage of people being shut out of society for not having quarterly injections, but who could have imagined the current set of restrictions just a couple of years ago?