What did the Catholic Church teach prior to that?
I think you'll find plenty of support for that dogma in Roman Catholic theology through the millennia.
That Jews were Christ killers, and that the currently living Jews are responsible for that supposed sin of their ancestors.
We witness truly epochal changes in the position of the Church.
Alex Murphy asked: What did the Catholic Church teach prior to that?
From one who studies Catholicism from ALL antiquity (not just the last 50 years of Vatican II), I say, that was a good observation Alex Murphy. I wonder why they would write that?
As far as the answer, I don't know. Did the church accuse the Jews collectively? I don't know. I don't really care either. However, you can bet a "CHANGE" in the year 1960+- is going to be strange. The Church got it wrong for 1960 years? Anyhow, it's Yahoo, and it's the secular newsmedia, so, this kind of propaganda is to be expected.
Those people that learn the faith from newspapers: "after their own lusts shall they heap to themselves teachers, .. turn away their ears from the truth, and shall be turned unto fables".
Nothing by me, but your answer may be found here: The Popes Against the Jews, Part 6:- http://beggarsallreformation.blogspot.com/2011/02/popes-against-jews-part-6-show-so-far.html
An understanding of Luther’s attitude toward the Jews can be seen here: http://tquid.sharpens.org/luther_Jews.htm
Peter did change the Jews with Jesus death in Acts 2, but we are all guilty of killing Christ, as my flesh and our is at enmity against God, and is irreformable (Rm. 8:7) ( if that’s a word). Paul, like Moses (being a type of him), was willing to be damned for their sake, (Ex. 32:32; Rm. 9:3) but also condemned them a whole and said, “wrath is come upon them to the uttermost,” as they harshly resisted the gospel, (1Thes. 2:16) with blindness resulting as a judgment. (Jn. 12:35,36)
But God promised a yet future reversing of the curse, and so all Israel (a remnant that is left) shall be saved, to the glory of God. (http://peacebyjesus.witnesstoday.org/israel-chosenorforgotten.html)