Madonna and Child with Saint Sebastian and Saint Vincent Ferrer

Madonna and Child with Saint Sebastian and Saint Vincent Ferrer or Madonna and Child with Saint Sebastian and Saint Thomas Aquinas is a 1506 oil on panel painting by Andrea Previtali, produced in Venice while he was still in the studio of Giovanni Bellini and contemporary with the same artist's "Madonna and Child" (Museum of Fine Arts (Budapest)). It is now in the Accademia Carrara in Bergamo, to which it passed from Guglielmo Lochis's collection in 1866. 
The saint on the right is not definitively identified and lacks the traditional attributes of either St Thomas Aquinas or St Vincent Ferrer. The work is signed "ANDREAS, NERGOMENSIS. DISSIPULUS IOVA.BELINI.P.XIT" and dated "MCCCCCVI", both on the base of the Madonna's marble throne. The signature is followed by a palm branch and an olive branch bound by a ribbon, a symbol which also appears on the artist's "St John the Baptist with Four Saints" (church of Santo Spirito, Bergamo), the picture cycle for palazzo Zogna and "Christ Blessing" (National Gallery, London). Also on the throne's base is a symbol, possibly YHS (the trigram of Bernardino of Siena) or more likely VHS ("Virgini Hominum Servatrici" or "To the Virgin, Servant of Mankind").