The extended Vigil of Pentecost may be celebrated on this feast.  The readings and psalms associated with the extended Vigil are newly included in the Lectionary for Mass Supplement, which was recently published in April of this year and announced in the March 2017 edition of the Liturgy Update.

The sequence Veni, Sancte Spiritus is obligatory only on Pentecost Sunday and not at the Vigil, unless, for pastoral reasons, the readings of Pentecost are proclaimed at the Vigil Mass.  The extended dismissal consisting of “Alleluia, Alleluia” is said or sung at both the Vigil Mass and on Pentecost Sunday itself.