There are three different level of issues related to the vaccines currently sold and used in our Western World:
(1) To know if the appropriation of products related to abortion is permissible for a Catholic who truly respects innocent life: all the teaching of the Church, particularly of the last popes, but the present one, instruct us that no;
(2) To know if it is prudent for an individual to take these vaccines (regardless of their organic relationship with the scourge of abortion) and here we remain in a perfectly debatable opinionable prudential discourse;
(3) To know if the State has the right, not in an abstract and/or universal fashion, but at this very particular time, to impose such a vaccine to the whole population it governs either by legal means or, even worse, by the use of any kind of social coercion.
As ethician, in this case I do not care about the moment or about the process of getting a good of unethical or dubious origins, as the problem has never been about knowing what is my personal degree of participation to evil deeds, which topics concerns mainly, if not solely, the people who work in that specific Pharma industry and not us potential patients of these produced goods: manipulating the limbs of a child while still alive in the womb of his mother or after having been cut in pieces beforehand might increase the intensity of the criminal act but does not cancel at any time its evil nature.
The various encyclicals, if carefully read, address the problematic of the participation with evil of the operators in that field: extending these reflections as such directly to the users/customers/patients is a bit of an intellectual stretch as these ones are not operators but solely beneficiary of the process.
The nature of ethical reflection here is about appropriation: when does appropriation becoming fencing, because this is the case when we do buy or enjoy a good evilly obtained, produced, proposed by someone else through stealing, killing, counterfeiting, you name them.
Because at the end this is the scenario: we have people who commit a crime (steeling a crown, killing an unborn baby), we have other people who do a first fencing of the outcomes of this crime (collecting the crown, the limbs of the little corpse), other people who transform these outcomes in something more palatable and easier to sell further (dismantling the crown, producing industrially human tissues for experiences, testing and production), and finally customers who can be aware or not of the origins of the good they buy for their own enjoyment (nice diamonds wedding ring, or getting a jab hoping to be safe from a disease).
This problematic is extremely well understood by the citizens and the consumers of our society and has nothing so complicated not to be understood by the people in the street: the notions of boycott/buycott have their deep ethical roots into the common sense understanding that it is immoral, against any ethics, to act as a fence for unethically acquired goods.
The big boycott campaigns of the past (I recall against GAP in the USA because of the sweatshops in Asia and South-America) or of the present (people boycotting Israeli products, or unfairly produced products by children workforces, or not-organic products) show that people perfectly understand that buying a product of supposed evil origins is, cut and clear, participating to an evil process, making it even more successful: appropriation of an evilly acquired good is guaranteeing to the whole chain of evil doers full success, and this is evil per se as it is about guaranteeing that the final cause of the evil doers is sucessfully satisfied.
This can be grounded back even to the Old Testament where appropriating and eating some evil food, because of its origins (like pork, mollusks, etc.) or its usages (the remains of religious sacrifices of other religions, etc.) was forbidden, i.e., boycotted.
The fact that the Catholic Ecclesiastic Structure’s Leadership of these days has not deemed necessary to recall that and has attempted to drown the fish within confusing considerations about remote, material participation while the fencing immorality is blatant and doing so avoiding pushing the Pharma into actively looking for much better ethical solutions, recalls me of those guys who were filtering gnats while swallowing camels.
All the doctrines developed in the cultural framework of the Catholic Church, whether we go back to St. Augustine, St. Thomas Aquinas, or the great social encyclicals, including those of the Pope Emeritus, see the State (empire, prince, Hegelian state as in the 19th and 20th centuries) as a guarantor (even identified by some with the Pauline Katekhòn) of the Common Good.
Matter-of-factly, the modern Western States have abdicated from the role of guaranteeing the participation and the enjoyment of said Common Good: instead of promoting virtues and behaviors satisfying the human nature which are the only means to achieve the Eudaimonia, the Happiness every human being is entitled to, it puts in place politics, laws, rules, and regulations which do promote vicious behaviors, against the human nature and finally against that happiness.
The modern States do not look anymore to a Common Good but, in the best case, only to a Greater, hence perfectly Utilitarian, Good where the interest of the individuals, of the families, and of the communities have no weight what-so-ever in the political evaluations. The “contract” between the State and the citizen is objectively broken and this show up here in Europe, where the State is obliged to coerce its own citizens because of that.