Acoording to Snopes, which I consider a reliable source, the modern measles (MMR) vaccine does not contain any fetal tissue whatsoever. It is also true to say that the stem cells it was originally derived from in the 1960s came from a legally aborted fetus in Sweden. This doesn’t cause me any angst personally, but I suppose I can see a point of view where it could cause some people angst. Morally though, why do they find it acceptable to put live babies at risk today because they have an objection to an obsolete technology? And rationally, the same people who oppose this obsolete technology are also resisting upgrades to modern technologies that rely on stem cells not isolated from fetuses and the even more recent mRNA ones that do not involve stem cells at all.