In light of the recent measles out break and discussion on vaccines here is some helpful answers from the National Catholic Bioethics Center:
What is the Church's teaching about the use of certain vaccines that have a distant historical association with abortion?
There are a number of vaccines that are made in descendent cells of aborted fetuses. Abortion is a grave crime against innocent human life. We should always ask our physician whether the product he proposes for our use has an historical association with abortion. We should use an alternative vaccine if one is available.
What does it mean when we say that these products are made in "descendent cells"?
Descendent cells are the medium in which these vaccines are prepared. The cell lines under consideration were begun using cells taken from one or more fetuses aborted almost 40 years ago. Since that time the cell lines have grown independently. It is important to note that descendent cells are not the cells of the aborted child. They never, themselves, formed a part of the victim's body.
How does one know when a particular vaccine has an association with abortion?
The cell lines WI-38 and MRC-5 are derived from tissue from aborted fetuses. Any product grown in the WI-38 and MRC-5 cell lines, therefore, has a distant association with abortion. The cells in these lines have gone through multiple divisions before they are used in vaccine manufacture. After manufacture, the vaccines are removed from the cell lines and purified. One cannot accurately say that the vaccines contain any of the cells from the original abortion.
What does one do if a physician recommends one of these vaccines?
Sometimes alternative products, which are not associated with these cell lines, are available for immunization against certain diseases. For example, there is a rabies vaccine (RabAvert) and a single dose mumps vaccine (Mumpsvax) without any association with abortion that are equally safe and effective. If doing so is practical, you should ask your physician to use an alternative vaccine, but there is no moral obligation to use products that are less effective or inaccessible. Parents should check with their physician regarding the efficacy and availability of these and any other vaccine.
Are there any vaccines for which there are no alternatives?
Unfortunately, at present there are no alternative vaccines available in the United States against rubella (German measles), varicella (chickenpox), and hepatitis A. All of these are grown in the cell lines WI-38 and/or MRC-5. (See the statement of the Pontifical Academy for Life for a listing of vaccines and their source).
What do I do if there is no alternative to a vaccine produced from these cell lines?
One is morally free to use the vaccine regardless of its historical association with abortion. The reason is that the risk to public health, if one chooses not to vaccinate, outweighs the legitimate concern about the origins of the vaccine. This is especially important for parents, who have a moral obligation to protect the life and health of their children and those around them.
What support is there in Church teaching for this position?
The Pontifical Academy for Life (ncbcenter.org/document.doc?id=7) issued in 2005 holds that one may use these products, despite their distant association with abortion, at least until such time as new vaccines become available.
What can I do to ensure that alternative vaccines will be made available?
You can write to the pharmaceutical companies that make these products and insist that they manufacture vaccines that can be used by all without moral reservation. Also, you can contact your local legislators about your concerns.
Am I free to refuse to vaccinate myself or my children on the grounds of conscience?
One must follow a certain conscience even if it errs, but there is a responsibility to inform one's conscience properly. There would seem to be no proper grounds for refusing immunization against dangerous contagious disease, for example, rubella, especially in light of the concern that we should all have for the health of our children, public health, and the common good.
Won't my use of these vaccines encourage others to destroy human life for research purposes?
Upon use, one should register a complaint with the manufacturer of the products as an acceptable form of conscientious objection. This signals opposition to the wider, morally reprehensible practice of using the unborn as little more than research material for science. There is no moral obligation to register such a complaint in order to use these vaccines. It should be obvious that vaccine use in these cases does not contribute directly to the practice of abortion since the reasons for having an abortion are not related to vaccine preparation.
Love, Fr. John