How Is a Catholic Supposed to Think About the COVID Vaccine?

The Church’s official teaching on vaccines requires a kind of nuance missing from today’s public life.

A black-and-white rosary that ends with a vaccine bottle
Getty; Paul Spella / The Atlantic

The Dutch molecular biologist Alex van der Eb had been studying viruses and vaccines for nearly two decades when, in 1973, he was met with what he took to be an exhilarating opportunity. Three years into their studies, van der Eb and his research partner Frank L. Graham had succeeded in isolating the genes in adenovirus 5 responsible for turning mammalian cells into tumor cells, and they were curious as to whether the effect, which they had demonstrated in rat cells, could be replicated in human cells.

For that, they needed human cells. Like many laboratories, van der Eb’s used donated human remains expressly released for medical research. On this particular day in 1973, those human remains happened to belong to a girl aborted legally at 18 weeks by an anonymous woman at a teaching hospital in Leiden, the Netherlands. That woman had consented to the use of the body for scientific purposes.

“I can clearly recall the day, now almost 50 years ago, that I had to perform that procedure,” van der Eb recently wrote to me in an email. “As I felt very responsible and particularly was aware that removing some fetal cells from the fetus in question could put a moral strain on my young staff, I did this myself.” He added, “I do remember that the fetus was a girl and outwardly normal.”

The cells he harvested led to some of the next half century’s most consequential scientific discoveries, including the development of the COVID-19 vaccines. In the years since that day, all of us have been living in the world that that woman, her child, and van der Eb in some small but crucial way created. And in those years, the Catholic Church has vociferously debated how to live in that world.

Among the United States’ religious groups, American Catholics appear quite willing to be vaccinated against COVID-19. White Catholics have registered a particularly high rate of vaccine acceptance, with 68 percent already vaccinated or planning to be vaccinated shortly, according to an April survey published by the Public Religion Research Institute. Only American Jews are more likely to seek vaccination. After all, strong arguments for vaccination from a Catholic standpoint have been advanced by none other than the pope himself. It’s nigh impossible to have missed the message, Catholic or not.

But there nevertheless remain Catholics in good standing who have thus far elected not to be vaccinated. These Catholics are notable among American opponents of vaccination, not exactly at home among those so suspicious of experts and institutions that they have developed overwhelming safety concerns, or those who mistrust or resent the Biden administration and the pro-vaccine crowd more generally, or the crunchy, off-the-grid libertarians who reject authority at large.

It isn’t that none of those notions arises among American Catholics who remain wary of the vaccines, only that Catholics also have reasons particular to their religious views of life, death, good, and evil that sharpen their opposition. In true Catholic fashion, whether to get vaccinated is a choice they have institutional support for deciding either way.

This story begins long before 1973. For Catholics, the origins of humankind speak to a certain tendency toward evildoing. Catholic moral theologians, therefore, have long grappled with the question of how Catholics ought to interact with a world laced with the remnants of others’ evil acts. This question arose in the earliest days of Christianity—Paul the Apostle, for instance, wrestled with whether early Christian converts could eat food offered in sacrifice to the pagan gods of Greece and Rome, or if doing so would in some sense draw the unwitting believer into idol worship.

In the mid-18th century, the Neapolitan priest and philosopher Saint Alphonsus Liguori built upon that premise and others as he began writing his magnum opus, Moral Theology. And he introduced a key distinction: formal versus material cooperation with evil.

Charles Camosy, a Fordham University theology professor and bioethics specialist, explained the difference to me this way. “One is always blameworthy for ‘formal’ cooperation with evil,” he wrote in a September email, “that is, cooperation in which one’s will is aligned with that of the evil-doer’s. (Think here about driving the get-away car for a bank robbery.) But one could instead have ‘material’ cooperation with evil, where one’s will is not so aligned. This kind of material cooperation happens all the time, both wittingly and unwittingly, and can be justified for proportionately serious reasons.”

This is a moral consideration people tend to contemplate whether they’re Catholic or not, Camosy pointed out. Consider, for instance, the purchase of fast-fashion clothing manufactured under dubious working conditions on another continent. How complicit is such a customer in the harm done to workers in that scenario?

“There is another important distinction to make,” Camosy went on, “between material cooperation that is remote and that which is proximate. In brief, the further removed one is from the evil when materially cooperating, the less serious of a reason one would need to justify it.”

A person buying clothing directly from a company that uses exploitative labor practices to generate lower prices, Camosy said, wouldn’t have a particularly strong argument for doing so. But another person buying that same piece of clothing secondhand at a thrift store would be “in a much different moral position.”

And that may well have been that: a complex moral framework suitable for dealing with the complex realities of living in a world wherein good and evil are often hopelessly entangled, sweatshops, sacrifices, and all.

But buying and selling is one thing. Living and dying is another.

I should tell you something about what followed van der Eb’s 1973 research: It is complicated. One of the unloveliest and least enlightening aspects of contemporary discourse is the tendency to presume that whatever one disagrees with must be very simple—not only simple, but also simply wrong; not only wrong, but also false, argued in bad faith, not even believed in the hearts of its own advocates. But life is arranged in far more intricate detail than that line of presumption would allow. People really do hold complicated, challenging beliefs. Misguided views really do contain, at times, occasional threads of worthwhile truth. Good and evil really are intertwined in this world, and we really do have to deal with that, somehow.

The fetal cell line that van der Eb extracted became known as HEK 293 and is still used frequently in medical research. The line has been used to study an enormous range of pharmaceuticals, from common over-the-counter drugs such as ibuprofen and aspirin to vaccines against lethal diseases such as tuberculosis, Ebola, and COVID-19.

For Catholics, the conundrum posed by the fruits of van der Eb’s research has to do with the roots of his process: Is willingly using products created from human remains procured from abortion ever morally permissible? The Congregation for the Doctrine of the Faith, a Vatican office devoted to defining and promulgating Catholic doctrine, issued a 2005 letter detailing an uneasy conclusion: Catholics have a duty, it said, to seek out alternative vaccines that were not developed using fetal cells, when those options exist. “As regards the diseases against which there are no alternative vaccines which are available and ethically acceptable, it is right to abstain from using these vaccines if it can be done without causing children, and indirectly the population as a whole, to undergo significant risks to their health,” the office wrote. “However, if the latter are exposed to considerable dangers to their health, vaccines with moral problems pertaining to them may also be used.”

Or, in common parlance: Receiving vaccines developed using fetal cell lines such as HEK 293 can be morally permissible, as long as there aren’t suitable alternatives and the risks posed by the illness itself are sufficiently serious. The Church’s position, complex and contingent as it was, left plenty of Catholics uncertain about how to consider the COVID-19 vaccines. Was the coronavirus dangerous enough to justify the vaccines? Some of them approached John Di Camillo, a staff ethicist at the National Catholic Bioethics Center, in Philadelphia. I asked him how he had been responding to the many queries he had received regarding how to weigh moral concerns about the origins of the vaccines against the urgent threat of the pandemic itself.

“We will explain to people very clearly that the Church has, without question, stated that it can be morally permissible to use these cell lines when there is a sufficiently serious reason to do so,” Di Camillo told me, provided all the usual caveats are in play: that “the Catholics themselves and their organizations be opposed, obviously, to abortion and to the use of the cell lines in research generally, and that there be active efforts to transform those industries and to seek alternatives.”

And yet: “We certainly made clear that people can in good conscience, as the Church has taught, utilize the vaccines … while at the same time they’re saying very clearly that this doesn’t mean it’s a nonissue. You know, they should not simply say, ‘Oh, well, the Church has said it’s okay. There’s nothing else to think about.’”

In the course of the pandemic, the Vatican has assured Catholics that they can receive COVID-19 vaccines without sinning—though not without troubling their conscience. There is a difference in the elaborate hierarchy of Catholic moral thought. Pope Francis, in typical pastoral fashion, has guided Catholics to think of vaccination as an “act of love”—which it is, I think.

And nothing van der Eb said to me made me feel any differently. In fact, what struck me about van der Eb was how he moved easily between tones—a rare ability. Without my prompting, he mentioned an emotion little acknowledged in conversations about the morality of vaccines derived from his research: gratitude. Not for what happened to the girl, which had already happened by the time they crossed paths and was, at any rate, beyond his control; nor for the cells themselves in a general and undifferentiated utilitarian sense, from which one could deduce a broader argument for reducing the value of people to the usefulness of their organs. But rather for what came of that day in the laboratory—of the possibilities that were available to him and to her and to all of us at the moment their fates intersected: some good, some hope, some life yet to be preserved.

“I feel a warmth and gratefulness to that little child who has contributed so much to science and humanity,” van der Eb said.

I dream of the souls that pass one another at the gateway between life and death, the ones coming and the ones going, and I try to make sense of what I owe all of them in this moment, in this plague. I have to give them the chance I can at living, beckon on the new, send off the others only when nature demands it. I am Catholic, and I am vaccinated, and I am, like van der Eb, grateful to that child who died decades ago. Some Catholics would read gratitude for the little girl as praise of her death, but that, too, is too simple. Gratitude grows in the wild, and is as touched by tragedy as anything else in nature. So it is, being human.