OMG! Booster shot may be ineffective against the Delta variant.

https://www.timesofisrael.com/liveblog_entry/report-14-israelis-have-caught-covid-19-despite-receiving-booster-shot/

14 Israelis had been infected despite getting booster shots.

This is indeed very worrisome.  Look like the Pfizer vaccine is ineffective against Delta.