ROME — The Vatican’s doctrinal office (CDF) declared Monday that in present circumstances “it is morally acceptable to receive Covid-19 vaccines that have used cell lines from aborted fetuses in their research and production process.”

In its “Note on the morality of using some anti-Covid-19 vaccines,” the Vatican hastened to observe that it is not morally licit to perform abortions in order to create vaccines or for any other reason.

Nonetheless, the use of vaccines against the coronavirus, which, in the course of research and production, “employed cell lines drawn from tissue obtained from two abortions that occurred in the last century” can be a moral option because the cooperation in the past evil is “remote.”

The Vatican said it was responding to several requests for guidance regarding the use of vaccines with morally questionable origins as well as a need to clear up “diverse and sometimes conflicting pronouncements in the mass media by bishops, Catholic associations, and experts.”

In its reflections, the CDF built on earlier Vatican pronouncements including the 2008 instruction Dignitas Personae issued by the same Congregation for the Doctrine of the Faith.

The text also notes that the Vatican has no intention of judging “the safety and efficacy of these vaccines,” but only to consider “the moral aspects of the use of the vaccines against Covid-19 that have been developed from cell lines derived from tissues obtained from two fetuses that were not spontaneously aborted.”

The key moral issue at play in such an evaluation is the question of cooperation in evil, or the participation in another person’s immoral action. The Catholic moral tradition distinguishes between formal cooperation, where a person shares in the immoral intention of another, and material cooperation, where a person’s actions are in some way related to another’s immoral act but without willing the immoral action.

The Catholic tradition considers formal cooperation in evil to always be immoral, whereas material cooperation may be moral or immoral depending on other factors, such as whether one’s actions directly enable the evil actions of another. In the present case, the CDF has determined that the use of vaccines that have been developed from cell lines originally obtained from an aborted fetus does not enable or encourage the immoral action of the abortion and that there is a proportionate serious reason to do so.

“The fundamental reason for considering the use of these vaccines morally licit is that the kind of cooperation in evil (passive material cooperation) in the procured abortion from which these cell lines originate is, on the part of those making use of the resulting vaccines, remote,” the text declares.

The CDF also states that in the present case, it is morally acceptable to receive Covid-19 vaccines that have used cell lines from aborted fetuses when other, ethically irreproachable vaccines are not available.

“It must therefore be considered that, in such a case, all vaccinations recognized as clinically safe and effective can be used in good conscience with the certain knowledge that the use of such vaccines does not constitute formal cooperation with the abortion from which the cells used in production of the vaccines derive,” the text states.

The CDF also insists that the licit use of such vaccines “does not and should not in any way imply that there is a moral endorsement of the use of cell lines proceeding from aborted fetuses.”

The Vatican corrects an earlier, controversial statement of the U.S. bishops, which erroneously declared that taking a coronavirus vaccine constitutes a moral obligation.

Practical reason “makes evident that vaccination is not, as a rule, a moral obligation and that, therefore, it must be voluntary,” the CDF declares.

The text adds that from the ethical point of view, “the morality of vaccination depends not only on the duty to protect one’s own health, but also on the duty to pursue the common good, which may “recommend vaccination, especially to protect the weakest and most exposed.”

The CDF note states that it is morally imperative for the pharmaceutical industry, governments and international organizations to ensure that vaccines “are also accessible to the poorest countries in a manner that is not costly for them.”