Pfizer effectiveness wanes faster than AZ (General)
Israel and US are already giving booster shots for Pfizer. That indicates it's running out of puff after about 4-6mths.
Interestingly, there's no call for a booster on the J&J, which was trashed by the media earlier.
This is becoming a marketing windfall for vaccines that perform poorly. In educational technology parlance, this is what is referred to as rewarding poor performance.