The Ethics and Public Policy Center has assembled a group of heavy-hitters who, together, try to allay the concerns that pro-lifers may have about taking these vaccines. From their statement:
While there is a technical causal linkage between each of the current vaccines and prior abortions of human persons, we are all agreed, that connection does not mean that vaccine use contributes to the evil of abortion or shows disrespect for the remains of unborn human beings. Accordingly, Catholics, and indeed, all persons of good will who embrace a culture of life for the whole human family, born and unborn, can use these vaccines without fear of moral culpability. . . .
The HEK293 cell line currently used around the globe in scientific research and those like it do not contain the remains of any human being and so its use does not show disrespect for human remains, any more than the contemporary use of products, such as roads or train lines, that were constructed by unjustly enslaved human beings, or use of land unjustly taken, shows disrespect for those victims in the distant past. . . .
To be perfectly clear, we are not saying that people are justified in using and promoting these vaccines because the great goods they provide offset the evil of appropriating a prior wicked action. Rather, we believe that there is no such impermissible cooperation or appropriation here. The attenuated and remote connection to abortions performed decades ago and the absence of any incentive for future abortions offer little if any moral reasons against accepting this welcome advance of science.
I find the statement wholly persuasive.