When Jesus mentioned the “one flock, one shepherd,” was he referring to the Catholic Church alone?

In John 10:16 Jesus says "I have other sheep that are not of this fold; I must lead them too, and they will heed my voice. So there shall be one flock, one shepherd." Does that one flock mean the One Holy Apostolic Catholic Church or does that include all the other Protestant churches in the world? What does the Church teach?