[Fuzz]

Originally Posted by Knut

https://www.cdc.gov/mmwr/volumes/70/wr/mm7038e1.htm

This is probably what places are referencing. Not sure where the 77% comes from.

VE for the Moderna vaccine was 93% at 14–120 days (median = 66 days) after receipt of the second vaccine dose and 92% at >120 days (median = 141 days) (p = 1.000). VE for the Pfizer-BioNTech vaccine was 91% at 14–120 days (median = 69 days) after receipt of the second vaccine dose but declined significantly to 77% at >120 days (median = 143 days) (p<0.001).

From the link.