"Having considered the previous cases, we arrive at the question of what kind of cooperation with abortion obtains when a parent decides to immunize a child against rubella. The parent has no intention of participating in abortion and, living in the present, has no connection whatsoever to the abortions performed in the past. Neither does the parent make use of the cells taken from an abortion, but makes use of a vaccine that was grown in descendant cells. The capacity of these cells to duplicate in culture shows that their use applies little to no pressure on others to perform abortions. There is an abundant supply. If there were some remaining level of cooperation here, it could only be remote. This cooperation would be completely permissible because 1) parents have no choice but to use these products if they wish to protect their children and society from these serious diseases; and 2) the good that parents are seeking to secure through vaccination exceeds any harm that might be caused by that use. Thus it would represent a very harsh judgment, in my opinion, if someone were to say that unborn children must face the risks of serious birth defects or even death because others feel an obligation to make a strong statement against the evil of abortion. The fault surely lies with the original tissue researchers and, less directly, with the pharmaceutical companies or those who made imprudent decisions at the time these products were first manufactured. The fault does not lie with the parents and surely not with the children who suffer the risk. If the above reasoning is correct, and there is no immoral cooperation with abortion in the use of these vaccines, then we are led back to the problem of conscience from an entirely new perspective. One who properly exercises conscience will recognize that he has a moral obligation to protect the life and health of his neighbors and that he must therefore ensure that he and his children are vaccinated as a correct means to that end. He will recognize that there is a moral question at issue in the use of vaccines, but he will also see that there can be no justification for risking the health and life of unborn children who have had absolutely no hand in the original wrongdoing. He will bear in mind that his own children will learn from his decision and that the occasion presents him with an opportunity to explain to them how to think about difficult moral problems. The formation of conscience is a responsibility that a parent has toward his child throughout his time in the home. What will the child learn from a parent who refuses to vaccinate him out of an exaggerated concern that the use of these vaccines is immoral? Hopefully, the entire event will pass without his notice."