Of course, people before Christ could have been and many were saved, and it was limited not only to Jҽωs. Gentiles who were outside of the Old Covenant could be saved through observing the Natural Law - this is how many Catholic exegetes interpret St Paul's teaching in Romans 2:
Romans 2:14-15 "For when the Gentiles, who have not the law, do by nature those things that are of the law; these having not the law are a law to themselves:
15 Who shew the work of the law written in their hearts, their conscience bearing witness to them, and their thoughts between themselves accusing, or also defending one another"
In this context "works of the law" are unlikely to mean Mosaic Law, since Gentiles were not part of the Old Covenant. Thus, "the law written in their hearts" must mean Natural Law, observance of which was salvific before the Incarnation.
St. Justin the Martyr, First Apology (2nd century): "We have been taught that Christ is the first-born of God, and we have declared above that He is the Word of whom every race of men were partakers; and those who lived reasonably are Christians, even though they have been thought atheists; as, among the Greeks, Socrates and Heraclitus, and men like them; and among the barbarians, Abraham, and Ananias, and Azarias, and Misael, and Elias, and many others whose actions and names we now decline to recount, because we know it would be tedious."