A U.S. Bishop, Strickland of Tyler, Texas, has publicly stated that people should reject any vaccine developed using aborted chlidren.

Strickland: “I renew my call that we reject any vaccine that is developed using aborted children. Even if it originated decades ago it still means a child’s life was ended before it was born & then their body was used as spare parts. We will never end abortion if we do not END THIS EVIL!” [Twitter.com]

Meanwhile, a couple of U.K. Bishops, Paul Mason and John Sherrington, have stated that Catholics have a moral obligation to receive a Covid-19 vaccine.

So, which is true. Do Catholics have a moral obligation to reject a Covid-19 vaccine, if it was developed using a cell line from an aborted fetus? Or do we have a moral obligation to accept the vaccine, to protect health and life?

A 2005 statement from the Pontifical Academy of Life [PDF file] explains that accepting a vaccine developed using an aborted fetus cell line is “a form of very remote mediate material cooperation, and thus very mild” in its cooperation with the original act of abortion. A 2017 Statement from the same Academy repeats this judgment, saying:

“The technical characteristics of the production of the vaccines most commonly used in childhood lead us to exclude that there is a morally relevant cooperation between those who use these vaccines today and the practice of voluntary abortion. Hence, we believe that all clinically recommended vaccinations can be used with a clear conscience and that the use of such vaccines does not signify some sort of cooperation with voluntary abortion.”

The PAL excludes any morally relevant cooperation with the acceptance of such vaccines. So any vaccine that is clinically recommended “can be used with a clear conscience.” The reason is that the original abortion was not carried out for the reason of obtaining cells; the abortion occurred decades ago; the cells used were never part of a fetus, but are derived from those cells by many generations of cell replication; and most vaccines using a cell line do not include any cells from the line in the vaccine itself.

Now, most importantly, not only vaccines by much research eventually arriving at different scientific insights and medical treatments at some point in the research may have used such a cell line. Separating which medical treatments at some point used such a cell line in its research and development, from those that had no such relationship is nearly impossible. A prescription drug may have been researched and developed across hundreds of studies on that subject area within medicine, and some few studies may have used an aborted fetal cell line. The fact that such cell lines are used is morally objectionable. But the patients cannot discern which treatments used those lines, and which did not.

Almost everyone who is speaking against vaccines developed from aborted fetal cell lines has received such a vaccine. The usual MMR vaccine (measles, mumps, and rubella) uses such a cell line. It is given to every child in the U.S. When I was in college, there was an outbreak of measles in college students because the MMR given that year was ineffective. (I discovered the first case of measles at my university, and met with the CDC epidemiologist who came to the college to investigate.) The students had to be revaccinated. A vaccine against chickenpox is also from a fetal cell line, as is ones against polio, rabies, and smallpox. We cannot, as a nation or a world, reject all these vaccines because of their remote material connection to an abortion many decades ago. The harm done by rejecting the vaccines greatly outweighs the slight good of declining to be very remotely involved in an abortion.

As for Covid-19 vaccines, the same principle applies. Research from hundreds of studies affects the development of any vaccine, and some of those studies may have used an aborted fetal cell line. But the relationship to the original gravely immoral act of abortion is very remote.

According to Church teaching on remote material cooperation, if the good consequences of the cooperative act morally outweigh the bad consequences of the act, it is permissible. But in the case of this “very remote mediate material cooperation”, the ordinary goods that result from a vaccine — protection of the individual and the society from a disease — is sufficient to justify the act. The moral weight of the cooperation is “very mild”.

Covid-19 is a very severe disease, which has killed 700,000 persons worldwide, and will likely kill millions of persons before the pandemic ends. For those who survive, the negative health consequences can be severe. Survivors can be left in a weakened state that greatly harms their quality of life. The moral weight of reception of a vaccine against Covid-19 is very grave, and the weight of the cooperation, if an aborted fetal cell line is used in the development of the vaccine is very light. So the vaccine is certainly moral to accept.

Moreover, there is a positive moral obligation to accept a Covid-19 vaccine, if it is safe and effective. The reason is that not only the healthy or life of the individual recipient is at issue. A society needs “herd immunity”, the protection of many individuals by the reception of a vaccine by the society. No vaccine is 100% effective. But if the vaccine is effective enough to obtain herd immunity, everyone is protected, including those for whom the vaccine failed and those who were unable to be vaccinated due to chronic illness, old age, young age, etc.

If a group of persons in any nation refuse the Covid-19 vaccine, we might not be able to obtain herd immunity from that vaccine. The reason is that the herd immunity threshold depends on how contagious the disease may be and how effective the vaccine may be. Covid-19 is very contagious and the first vaccines against it might not be highly effective, so the society needs as many persons as possible to accept the vaccine, in order to protect the whole society, especially the weakest persons (who can’t receive the vaccine themselves).

This results in a moral obligation to accept a vaccine against Covid-19, if it is safe and effective. Of course, an unsafe vaccine, one with extensive common side effects, might not be morally obligatory. Also, a vaccine that has such limited effectiveness that herd immunity would not result even if 100% of persons are vaccinated, would have lower moral weight and might not be morally required.

What is happening today is that conservative Catholic are responding to the Covid-19 pandemic, not according to the will of God, nor according to the dictates of a well-formed conscience, but as a pseudo-political party, displaying behaviors that are contrary to prudence and morality, merely to proclaim that they are part of a certain subculture. If you are a conservative or traditionalist Catholic, your subculture tells you to reject the vaccine as a way to proclaim to the world that you are conservative or traditionalist. The subculture tells you to reject wearing masks, to disdain the concerns of spreading the virus, if it interferes with Mass or reception of Communion. The subculture makes the moral decision for you, so as to reinforce itself, and so as to rebuke those it sees as its enemies. And this is not Christ-like behavior.

Wear the mask. Receive Communion on the hand. Be very cautious at Mass, or go to Mass online. If there is a safe and effective Covid-19 vaccine, accept it (unless advised by your physician not to do so). Be Christian, first and foremost. Don’t let any subculture in the Church tell you how to follow Jesus .

I understand the desire to end abortion. But it will not happen by means of fighting against vaccines. The path to the end of abortion is chastity. Abortion and contraception exist to serve the sexual sins of a sinful society. Only when society abandons those sins will we be able to end abortion and abortifacient contraception.

Accept the vaccine.

Ronald L. Conte Jr.