Everyone in the Latin Rite everywhere is to kneel from the Sanctus to the Great Amen. In the United States, everyone in the Latin Rite is to kneel from the Agnus Dei to going up for Communion.
Actually, kneeling for the
whole Eucharistic Prayer is not a universal practice in the Ordinary Form. The Latin GIRM speaks of kneeling from the epiclesis until after the priest’s genuflection after the consecration of the wine:
Genuflectant vero, nisi valetudinis causa, vel ob angustiam loci vel frequentiorem numerum adstantium aliasve rationabiles causas impediantur, ad consecrationem. Hi vero qui non genuflectunt ad consecrationem, inclinationem profundam peragant dum sacerdos genuflectit post consecrationem. … Ubi mos est, populum ab acclamatione Sanctus expleta usque ad finem Precis eucharisticae et ante Communionem quando sacerdos dicit Ecce Agnus Dei genuflexum manere, hic laudabiliter retinetur. (IGMR 43)
That says roughly: They kneel, unless prevented for good reason, for the Consecration. [This **includes the epiclesis, because GIRM 179 directs the
deacon to kneel at the epiclesis, and it only makes sense that if the
deacon at the altar has to kneel starting at the epiclesis, so should the non-ordained faithful.] If they cannot kneel during the consecration, they make a profound bow when the priest genuflects. … Where it is the custom of the people to kneel from after the
Sanctus until the end of the Eucharistic Prayer, and to kneel as the priest says “Behold, the Lamb of God…”, this is (or “may be”) laudably retained.
It’s in the US (and perhaps other places) that we kneel for the whole Eucharistic Prayer:
In the dioceses of the United States of America, they should kneel beginning after the singing or recitation of the Sanctus until after the Amen of the Eucharistic Prayer, except when prevented on occasion by reasons of health, lack of space, the large number of people present, or some other good reason. Those who do not kneel ought to make a profound bow when the priest genuflects after the consecration. (GIRM 43)